Prosthetic heart valve

ABSTRACT

A prosthetic heart valve can include a radially collapsible and expandable annular frame having a plurality of struts defining openings. The prosthetic heart valve can further include a plurality of leaflets that regulate the flow of blood through the frame. The prosthetic heart valve can also include a sealing member mounted on the frame and having an inner layer and an outer layer. At least the outer layer is mounted on the outside of the frame, and the inner layer covers at least the openings in the frame between adjacent cusp portions of adjacent leaflets and the inner layer does not cover one or more openings in the frame at locations facing the outflow surfaces of the leaflets to permit retrograde blood to flow through the one or more uncovered openings in the frame and into space between the outer layer and the frame.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. ProvisionalApplication No. 62/369,678, filed Aug. 1, 2016, which is incorporatedherein by reference.

FIELD

The present disclosure concerns embodiments of a prosthetic heart valve.

BACKGROUND

The human heart can suffer from various valvular diseases. Thesevalvular diseases can result in significant malfunctioning of the heartand ultimately require replacement of the native valve with anartificial valve. There are a number of known artificial valves and anumber of known methods of implanting these artificial valves in humans.

Various surgical techniques may be used to replace or repair a diseasedor damaged valve. Due to stenosis and other heart valve diseases,thousands of patients undergo surgery each year wherein the defectivenative heart valve is replaced by a prosthetic valve. Another lessdrastic method for treating defective valves is through repair orreconstruction, which is typically used on minimally calcified valves.The problem with surgical therapy is the significant risk it imposes onthese chronically ill patients with high morbidity and mortality ratesassociated with surgical repair.

When the native valve is replaced, surgical implantation of theprosthetic valve typically requires an open-chest surgery during whichthe heart is stopped and patient placed on cardiopulmonary bypass (aso-called “heart-lung machine”. In one common surgical procedure, thediseased native valve leaflets are excised and a prosthetic valve issutured to the surrounding tissue at the valve annulus. Because of thetrauma associated with the procedure and the attendant duration ofextracorporeal blood circulation, some patients do not survive thesurgical procedure or die shortly thereafter. It is well known that therisk to the patient increases with the amount of time required onextracorporeal circulation. Due to these risks, a substantial number ofpatients with defective native valves are deemed inoperable becausetheir condition is too frail to withstand the procedure. By someestimates, more than 50% of the subjects suffering from valve stenosiswho are older than 80 years cannot be operated on for valve replacement.

Because of the drawbacks associated with conventional open-heartsurgery, percutaneous and minimally-invasive surgical approaches aregarnering intense attention. In one technique, a prosthetic valve isconfigured to be implanted in a much less invasive procedure by way ofcatheterization. For instance, U.S. Pat. Nos. 5,411,522 and 6,730,118,which are incorporated herein by reference, describe collapsibletranscatheter heart valves that can be percutaneously introduced in acompressed state on a catheter and expanded in the desired position byballoon inflation or by utilization of a self-expanding frame or stent.

An important design parameter of a transcatheter heart valve is thediameter of the folded or crimped profile. The diameter of the crimpedprofile is important because it directly influences the physician'sability to advance the transcatheter heart valve through the femoralartery or vein. More particularly, a smaller profile allows fortreatment of a wider population of patients, with enhanced safety.Another important design parameter is control of perivalvular leakagearound the valve, which can occur for a period of time following initialimplantation.

SUMMARY

In one representative embodiment, a prosthetic heart valve comprises anannular frame comprising an inflow end and an outflow end and beingradially collapsible and expandable between a radially collapsedconfiguration and a radially expanded configuration, wherein the framecomprises a plurality of struts defining openings. The prosthetic heartvalve can further comprise a valvular structure mounted within the frameand comprising a plurality of leaflets that regulate the flow of bloodthrough the frame, wherein each leaflet comprises an inflow surface, anoutflow surface, and a cusp edge portion that is fixed relative to theframe. The prosthetic heart valve can also comprise a sealing membermounted on the frame and comprising an inner layer and an outer layer.At least the outer layer is mounted on the outside of the frame, and theinner layer covers at least the openings in the frame between adjacentcusp portions of adjacent leaflets and the inner layer does not coverone or more openings in the frame at locations facing the outflowsurfaces of the leaflets to permit retrograde blood to flow through theone or more uncovered openings in the frame and into space between theouter layer and the frame.

In some embodiments, the cusp edge portions of the leaflets have acurved, scalloped shape and the inner layer of the sealing membercomprises a plurality of triangular shaped portions that are mounted onthe frame at locations between adjacent cusp edge portions of adjacentleaflets.

In some embodiments, the inner layer does not cover any openings in theframe at locations facing the outflow surfaces of the leaflets.

In some embodiments, the inner layer is mounted on the outer surface ofthe frame.

In some embodiments, the inner layer is mounted on the inner surface ofthe frame.

In some embodiments, the outer layer is shape set such that it extendsradially away from the frame when the frame is in the radially expandedconfiguration.

In some embodiments, the outer layer comprises a shape set fabric.

In some embodiments, the outer layer comprises a lower tapered wallsection that extends outwardly from the frame in a direction from theinlet end to the outlet end, an upper tapered wall section that extendsoutwardly from the frame in a direction from the outlet end to the inletend, and a central wall section that extends between the lower and uppertapered wall sections.

In some embodiments, the cusp edge portion of each leaflet is fixedrelative to the frame by a connecting skirt that is connected to anddisposed between the frame and the cusp edge portion of the leaflet,wherein each connecting skirt is sutured to struts of the frameextending in a diagonal line from the inlet end to the out end of theframe.

In some embodiments, wherein each connecting skirt comprises two layersof material sutured to the cusp edge portion of a leaflet and to strutsof the frame.

In some embodiments, each leaflet comprises opposing upper tabs onopposite sides of the leaflet and opposing lower tabs on opposite sidesof the leaflets below the upper tabs, wherein each upper tab is pairedwith an adjacent upper tab of an adjacent leaflet to form a plurality ofcommissures, and wherein each lower tab is folded to form at least onefold layer along the cusp edge portion of the respective leaflet.

In some embodiments, each leaflet is unattached to the frame atlocations between the upper tabs and the lower tabs.

In some embodiments, each leaflet is formed with a gap between the uppertab and the lower tab on each side of the leaflet.

In some embodiments, at least one reinforcing chord extends along thecusp edge portion of each leaflet and underneath each commissure.

In another representative embodiment, a prosthetic heart valve comprisesan annular frame comprising an inflow end and an outflow end and beingradially collapsible and expandable between a radially collapsedconfiguration and a radially expanded configuration. The prostheticheart valve can also comprise a valvular structure mounted within theframe and comprising a plurality of leaflets that regulate the flow ofblood through the frame. Each leaflet can comprise opposing upper tabson opposite sides of the leaflet, opposing lower tabs on opposite sidesof the leaflets below the upper tabs, a cusp edge portion extendingbetween the lower tabs, the cusp edge portion being fixed relative tothe frame, wherein each upper tab is paired with an adjacent upper tabof an adjacent leaflet to form a plurality of commissures that are fixedrelative to the frame, and wherein each lower tab is folded to form atleast one fold layer along the cusp edge portion of the respectiveleaflet.

In some embodiments, opposing side edges of the leaflets between theupper tabs and the lower tabs are unattached to the frame.

In some embodiments, the opposing side edges of the leaflets are formedwith gaps between the upper tabs and the lower tabs where the side edgesare unattached to the frame.

In some embodiments, the prosthetic heart valve can comprise a sealingmember mounted on the frame and comprising an inner layer and an outerlayer, wherein at least the outer layer is mounted on the outside of theframe, and the inner layer covers at least openings in the frame betweenadjacent cusp edge portions of adjacent leaflets and the inner layer hasuncovered areas at locations facing the outflow surfaces of the leafletsto permit retrograde blood to flow through the openings in the frame andinto space between the outer layer and the frame.

In some embodiments, a reinforcing chord extends along and is secured tothe cusp edge portion of each leaflet and the at least one fold layer ofeach lower tab.

In another representative embodiment, a prosthetic heart valve comprisesan annular frame comprising an inflow end and an outflow end and beingradially collapsible and expandable between a radially collapsedconfiguration and a radially expanded configuration. The prostheticheart valve can further include a valvular structure mounted within theframe and comprising a plurality of leaflets that regulate the flow ofblood through the frame. Each leaflet can comprise opposing tabs onopposite sides of the leaflet and a cusp edge portion between the tabs,the cusp edge portion being fixed relative to the frame, wherein eachtab is paired with an adjacent tab of an adjacent leaflet to form aplurality of commissures that are fixed relative to the frame, andwherein each leaflet has opposing edges between the tabs and the cuspedge portions that are unattached to the frame, allowing blood to flowbetween the frame and the unattached edges.

In some embodiments, the unattached edges are spaced radially inwardlyof the frame.

In some embodiments, the tabs of each leaflet comprise upper tabs thatare paired with adjacent upper tabs of adjacent leaflets to form thecommissures, and each leaflet further comprises opposing lower tabs onopposite sides of the leaflets below the upper tabs, the lower tabsbeing spaced from the upper tabs by the unattached edges, wherein thelower tabs are folded against the cusp edge portion of the leaflet.

In some embodiments, a reinforcing chord extends along and secured tothe cusp edge portion of each leaflet and traverses the space underneatheach commissure.

In some embodiments, each unattached edge of a leaflet can coapt with anadjacent unattached edge of an adjacent leaflet under the flow ofretrograde blood and can separate from the adjacent unattached edgeunder the flow of antegrade blood.

In another representative embodiment, a prosthetic heart valve comprisesan annular frame comprising an inflow end and an outflow end and beingradially collapsible and expandable between a radially collapsedconfiguration and a radially expanded configuration. The prostheticheart valve can further comprise a valvular structure mounted within theframe and comprising a plurality of leaflets that regulate the flow ofblood through the frame, wherein each leaflet comprises opposing tabs onopposite sides of the leaflet and a cusp edge portion between the tabs,wherein each tab is paired with an adjacent tab of an adjacent leafletto form a plurality of commissures that are connected to the frame. Thecusp edge portion of each leaflet can connected to the frame by aconnecting skirt that is connected to and disposed between the frame andthe cusp edge portion of the leaflet, wherein each connecting skirt issutured to struts of the frame extending in a diagonal line from theinlet end to the out end of the frame.

In some embodiments, the cusp edge portion of each leaflet is foldedtoward the outlet end of the frame.

In some embodiments, each connecting skirt is sutured to the cusp edgeportion of a leaflet and to the frame.

In some embodiments, a reinforcing chord is secured to each cusp edgeportion opposite a respective connecting skirt, the reinforcing chorddefining a bending axis for a respective leaflet.

In some embodiments, each connecting skirt prevents the cusp edgeportion of a respective leaflet from contacting the inner surface of theframe.

In some embodiments, the cusp edge portions are not supported by anymetal components inside the frame.

In some embodiments, each connecting skirt comprises two layers ofmaterial sutured to the cusp edge portion of a leaflet and to the frame.

In some embodiments, each connecting skirt supports the cusp edgeportion of a leaflet at a location spaced radially inwardly from theinner surface of the frame

In another representative embodiment, a prosthetic heart valve comprisesan annular frame comprising an inflow end and an outflow end and beingradially collapsible and expandable between a radially collapsedconfiguration and a radially expanded configuration, wherein the framecomprises a plurality of struts defining openings. The prosthetic heartvalve can include a valvular structure mounted within the frame andcomprising a plurality of leaflets that regulate the flow of bloodthrough the frame, wherein each leaflet comprises an inflow surface, anoutflow surface, opposing upper tabs on opposite sides of the leaflet,opposing lower tabs on opposite sides of the leaflets below the uppertabs, a cusp edge portion extending between the lower tabs. Each uppertab can be paired with an adjacent upper tab of an adjacent leaflet toform a plurality of commissures that are fixed relative to the frame,and each lower tab can be folded to form at least one fold layer alongthe cusp edge portion of the respective leaflet. The cusp edge portionof each leaflet can be connected to the frame by a connecting skirt thatis connected to and disposed between the frame and the cusp edge portionof the leaflet, wherein each connecting skirt is sutured to struts ofthe frame extending in a diagonal line from the inlet end to the out endof the frame. Each leaflet can have opposing edges between the uppertabs and the lower tabs that are unattached to the frame, with theunattached edges being spaced radially inwardly of the frame, allowingblood to flow between the frame and the unattached edges. The prostheticheart valve can also include a sealing member mounted on the frame andcomprising an inner layer and an outer layer. At least the outer layeris mounted on the outside of the frame, and the inner layer covers atleast the openings in the frame between adjacent cusp portions ofadjacent leaflets and the inner layer does not cover one or moreopenings in the frame at locations facing the outflow surfaces of theleaflets to permit retrograde blood to flow through the one or moreuncovered openings in the frame and into space between the outer layerand the frame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B are perspective views of a prosthetic heart, according toone embodiment.

FIG. 1C is an enlarged, perspective view of the area beneath one of thecommissures of the prosthetic heart valve of FIGS. 1A-1B.

FIG. 2 is a side elevation of the sealing member of the prosthetic heartvalve of FIG. 1.

FIG. 3 is a perspective, sectional view of the sealing member of FIG. 1.

FIG. 4 is a cross-sectional view of the prosthetic heart valve of FIG.1, showing the flow of retrograde blood through the valve.

FIG. 5 is an enlarged perspective view showing a portion of the insideof the prosthetic heart valve of FIG. 1.

FIG. 6 shows a strip of fabric that can be used to form a sealingmember, such as the sealing member of FIG. 3.

FIGS. 7A-7B are perspective views of exemplary tubular bodies that canbe used to form a sealing member for a prosthetic heart valve.

FIG. 8 is a perspective view of a partially assembled prosthetic heartvalve showing the attachment of leaflets using connecting skirts,according to one embodiment.

FIG. 9 is a plan view of a leaflet and a connecting skirt used in theprosthetic heart valve of FIG. 8.

FIGS. 10, 10A, 11A, and 11B are various views showing the attachment ofthe connecting skirt and the leaflet of FIG. 9.

FIGS. 12, 12A, and 12B are various views showing the connection of theconnecting skirt of FIG. 9 to the frame of the prosthetic valve of FIG.8.

FIG. 13A is a perspective view of a frame of a prosthetic heart valveand leaflets mounted inside the frame, according to one embodiment.

FIG. 13B is an enlarged view of a portion of the frame and one of theleaflets of FIG. 13A.

FIG. 14 is a plan view of a leaflet that can be used in a prostheticheart valve, according to one embodiment.

FIGS. 15A, 15B, 15C, 15D, 16, 17, 18, 19, 20, 21, 22, and 23 showvarious ways of connecting the cusp edge portion of a leaflet to a frameof a prosthetic heart valve using a connecting skirt.

FIG. 24 is an enlarged, perspective view of the inside of a prostheticheart valve, showing another way of connecting the cusp edge portion ofa leaflet to the frame of the valve.

FIGS. 25A, 25B, 26, 27, 28, 29, 30, 31, and 32 show alternative ways ofconnecting the cusp edge portion of a leaflet to a frame of a prostheticheart valve, with and without a connecting skirt.

FIG. 33 is a plan view of a leaflet that can be used in a prostheticheart valve, according to one embodiment.

FIGS. 34, 35, and 36 show the formation of one-half of a commissureusing the leaflet of FIG. 33, according to one embodiment.

FIG. 37 is a cross-sectional view of a commissure formed from twoleaflets of the type shown in FIG. 33, according to one embodiment.

FIG. 38 is a cross-sectional view of a commissure formed from twoleaflets of the type shown in FIG. 33, according to another embodiment.

FIG. 39 is a plan view of a leaflet that can be used in a prostheticheart valve, according to another embodiment.

FIG. 40 is a plan view of a leaflet that can be used in a prostheticheart valve, according to another embodiment.

FIGS. 41, 42, 43, 44, and 45 show the formation of a commissure from twoof leaflets of the type shown in FIG. 40, according to one embodiment.

FIG. 46 is a cross-sectional view of a commissure formed from twoleaflets of the type shown in FIG. 40, according to one embodiment.

FIG. 47 is a cross-sectional view of a commissure formed from twoleaflets of the type shown in FIG. 33, according to another embodiment.

FIG. 48 is a cross-sectional view of a commissure formed from twoleaflets of the type shown in FIG. 40, according to another embodiment.

FIG. 49 is a plan view of a leaflet that can be used in a prostheticheart valve, according to another embodiment.

FIGS. 50-51 are cross-sectional views of two embodiments of a commissureformed from two leaflets of the type shown in FIG. 49.

FIGS. 52, 53, 54, and 55 are various views showing the attachment of thecommissure of FIG. 50 or 51 to the frame of a prosthetic heart valveusing a commissure attachment member.

FIG. 56 is a cross-sectional view of another embodiment of a commissureformed from two leaflets of the type shown in FIG. 33.

FIGS. 57 and 58 are side elevation and perspective views, respectively,of a prosthetic heart valve, according to another embodiment.

FIG. 59 is a plan view of the sealing member of the prosthetic heartvalve of FIGS. 57-58, shown in a flattened configuration.

FIGS. 60 and 61 are perspective and cross-sectional views, respectively,of a prosthetic heart valve, according to another embodiment.

FIGS. 62, 63, and 64 show the sealing member of the prosthetic heartvalve of FIGS. 60-61 being mounted on the frame of the valve.

FIGS. 65 and 66 are perspective views of a prosthetic heart valve,according to another embodiment.

FIG. 67 is a perspective view of a portion of the prosthetic heart valveof FIGS. 65-66.

FIG. 68 is a perspective view of the sealing member of the prostheticheart valve of FIGS. 65-66.

FIG. 69 is a cross-sectional view showing the attachment of the cuspedge portion of a leaflet to a connecting skirt, according to anotherembodiment.

FIG. 70 is a plan view of an embodiment of a connecting skirt forconnecting the cusp edge portion of a leaflet to a frame, shown in theflattened configuration.

FIG. 71 is a side elevation view of the frame of the prosthetic heartvalve of FIGS. 65-66.

FIG. 72 shows the mounting of a valve assembly inside of the frame ofFIG. 71, according to one embodiment.

FIG. 73 is an enlarged view of a portion of the frame and the valveassembly of FIG. 72.

FIG. 74 is a perspective view of a leaflet of the prosthetic heart valveof FIGS. 65-66.

FIG. 75A is a plan view of the leaflet of FIG. 74, shown in a flattenedconfiguration.

FIG. 75B is a plan view of the leaflet of FIG. 74 and the connectingskirt of FIG. 70 positioned along the cusp edge portion of the leaflet.

FIG. 76 is a plan view of an embodiment of a commissure attachmentmember, shown in a flattened configuration.

FIGS. 77 and 78 are perspective and cross-sectional views, respectively,of one of the commissures of the prosthetic heart valve of FIGS. 65-66.

FIGS. 79 and 80 are perspective and top plan views, respectively, of aprosthetic heart valve, according to another embodiment.

FIGS. 81 and 82 are perspective and top plan views, respectively, of aprosthetic heart valve, according to another embodiment.

FIGS. 83 and 84 are perspective views of a prosthetic heart valve,according to another embodiment.

FIGS. 85 and 86 are side and top plan views, respectively, of one of thecommissures of the prosthetic valve of FIGS. 83-84.

DETAILED DESCRIPTION

The present disclosure concerns embodiments of implantable prostheticdevices and, in particular, implantable prosthetic valves, and methodsfor making such devices. In particular embodiments, the prostheticdevice comprises a prosthetic heart valve, and can be configured to beimplanted in any of the native heart valves (aortic, mitral, pulmonary,and tricuspid). In addition, the prosthetic heart valve can be, forexample, a transcatheter heart valve, a surgical heart valve, or aminimally-invasive heart valve. The prosthetic valve also can compriseother types of valves implantable within other body lumens outside ofthe heart or heart valves that are implantable within the heart atlocations other than the native valves, such as trans-atrial ortrans-ventricle septum valves.

The disclosed prosthetic heart valves are particularly suited forimplantation in the native aortic valve. In the context of a prostheticaortic valve, the terms “lower” and “upper” are used interchangeablywith the terms “inflow” and “outflow”, respectively, for convenience.Thus, for example, the lower end of the prosthetic valve is its inflowend and the upper end of the prosthetic valve is its outflow end in theorientation shown in the drawings. However, it should be understood thatthe prosthetic valve can be implanted in the reverse orientation. Forexample, for implantation at the mitral valve position, the upper end ofthe prosthetic valve is the inflow end and the lower end of the valve isthe outflow end.

FIG. 1A is a perspective view of a prosthetic heart valve 10, accordingto one embodiment. The illustrated valve is adapted to be implanted inthe native aortic annulus, although in other embodiments it can beadapted to be implanted in the other native annuluses of the heart. Thevalve 10 can have three main components: a stent, or frame, 12, avalvular structure 14, and a sealing member 16. FIG. 1B is a perspectiveview of the prosthetic valve 10 with the components on the outside ofthe frame 12 (including the sealing member 16) shown in transparentlines for purposes of illustration.

The valvular structure 14 can comprise three leaflets 20, collectivelyforming a leaflet structure, which can be arranged to collapse in atricuspid arrangement, although in other embodiments there can begreater or fewer number of leaflets (e.g., one or more leaflets 20). Thelower edge of leaflet structure 14 desirably has an undulating, curvedscalloped shape. By forming the leaflets with this scalloped geometry,stresses on the leaflets are reduced, which in turn improves durabilityof the valve. Moreover, by virtue of the scalloped shape, folds andripples at the belly of each leaflet (the central region of eachleaflet), which can cause early calcification in those areas, can beeliminated or at least minimized. The scalloped geometry also reducesthe amount of tissue material used to form leaflet structure, therebyallowing a smaller, more even crimped profile at the inflow end of thevalve. The leaflets 20 can be formed of pericardial tissue (e.g., bovineor porcine pericardial tissue), biocompatible synthetic materials, orvarious other suitable natural or synthetic materials as known in theart and described in U.S. Pat. No. 6,730,118, which is incorporated byreference herein.

Each leaflet 20 can be coupled to the frame 12 along its inflow edge 30(the lower edge in the figures; also referred to as “cusp edges”) and atcommissures 32 of the valvular structure 14 where adjacent portions oftwo leaflets are connected to each other, as further described below.

The frame 12 can be made of any of various suitableplastically-expandable materials (e.g., stainless steel, etc.) orself-expanding materials (e.g., Nitinol) as known in the art. Whenconstructed of a plastically-expandable material, the frame 12 (and thusthe prosthetic valve 10) can be crimped to a radially compressed stateon a delivery catheter and then expanded inside a patient by aninflatable balloon or any suitable expansion mechanism. When constructedof a self-expandable material, the frame 12 (and thus the prostheticvalve 10) can be crimped to a radially compressed state and restrainedin the compressed state by insertion into a sheath or equivalentmechanism of a delivery catheter. Once inside the body, the prostheticvalve can be advanced from the delivery sheath, which allows the valveto expand to its functional size.

Suitable plastically-expandable materials that can be used to form theframe 12 include, without limitation, stainless steel, a nickel basedalloy (e.g., a cobalt-chromium or a nickel-cobalt-chromium alloy),polymers, or combinations thereof. In particular embodiments, frame 12is made of a nickel-cobalt-chromium-molybdenum alloy, such as MP35N™(tradename of SPS Technologies), which is equivalent to UNS R30035(covered by ASTM F562-02). MP35N™/UNS R30035 comprises 35% nickel, 35%cobalt, 20% chromium, and 10% molybdenum, by weight. It has been foundthat the use of MP35N to form frame 12 provides superior structuralresults over stainless steel. In particular, when MP35N is used as theframe material, less material is needed to achieve the same or betterperformance in radial and crush force resistance, fatigue resistances,and corrosion resistance. Moreover, since less material is required, thecrimped profile of the frame can be reduced, thereby providing a lowerprofile valve assembly for percutaneous delivery to the treatmentlocation in the body.

The frame 12 in the illustrated embodiment comprises a plurality ofcircumferentially extending rows of angled struts 22 defining rows ofcells, or openings, 24 of the frame. The frame 12 can have a cylindricalor substantially cylindrical shape having a constant diameter from aninflow end 26 to an outflow end 28 of the frame as shown, or the framecan vary in diameter along the height of the frame, as disclosed in USPublication No. 2012/0239142, which is incorporated herein by reference.

The sealing member 16 in the illustrated embodiment is mounted on theoutside of the frame 12 and functions to create a seal against thesurrounding tissue (e.g., the native leaflets and/or native annulus) toprevent or at least minimize paravalvular leakage. The sealing member 16can comprise an inner layer 34 (which can be in contact with the outersurface of the frame 12) and an outer layer 36. The sealing member 16can be connected to the frame 12 using suitable techniques ormechanisms. For example, the sealing member 16 can be sutured to theframe 12 via sutures 38 that can extend around the struts 22 and throughthe inner layer 34. In alternative embodiments, the inner layer 34 canbe mounted on the inner surface of the frame 12, while the outer layer36 is on the outside of the frame.

The outer layer 36 can be configured or shaped to extend radiallyoutward from the inner layer 34 and the frame 12 when the prostheticvalve 10 is deployed. As best shown in FIG. 3, when the prosthetic valveis fully expanded outside of a patient's body, the outer layer 36 canexpand away from the inner layer 34 to create a space 40 between the twolayers. Thus, when implanted in the body, this allows the outer layer 36to expand into contact with the surrounding tissue.

In the illustrated embodiment, the outer layer 36 comprises a lowertapered wall section 36 a that extends outwardly from the frame in adirection from the inlet end to the outlet end, an upper tapered wallsection 36 b that extends outwardly from the frame in a direction fromthe outlet end to the inlet end, and a central wall section 36 c thatextends between the lower and upper tapered wall sections. The centralwall section 36 c can extend parallel to the longitudinal axis of theprosthetic valve as shown. In alternative embodiments, the upper andlower wall sections can extend perpendicularly relative to thelongitudinal axis of the prosthetic valve. In alternative embodiments,the outer layer 36 can be formed by connecting together (such as bystitching) separate fabric components (for example, separate pieces ofmaterial for each wall section 36 a, 36 b, 36 c) to form athree-dimensional structure without shape setting.

The inner layer 34 desirably is formed with at least one aperture oropening, and more desirably a plurality of apertures, or openings, 42(FIG. 5). As best shown in FIG. 4, retrograde blood (indicated by arrows44) can flow along the outside of the leaflets 20, through the cells 24of the frame, through the openings 42 in the inner layer 34 and into thespace 40 between the inner and outer layers 34, 36, to facilitateexpansion of the sealing member 16 and creating a seal against thesurrounding tissue. In some embodiments, the outer layer 36 can beformed with a plurality of apertures, or openings, which can allow bloodto flow into the sealing member at least during valve deployment.

In the illustrated embodiment, the inner layer 34 is formed with one ormore openings 42 along the portions of the inner layer that face theoutflow surface 70 of the leaflets (the areas of the frame between thecommissures) to allow retrograde blood to flow through the frame atthose locations. The portions of the inner layer 34 covering the framein the areas between the cusp edge portions of the leaflets completelycover the openings in the frame at those locations to prevent antegradeblood from flowing through the frame at those locations. In alternativeembodiments, the inner layer can have portions that cover the areas ofthe frame between the cusp edge portions of the frame and cut-outsections along the portions of the frame facing the outflow surface ofthe leaflets (see the sealing members 702, 802, described below).

As shown in FIG. 5, the openings 42 can be centered at junctions 50where the frame struts 22 intersect, which inhibits material of theinner layer 34 surrounding the openings from protruding inwardly throughthe frame and contacting the leaflets.

The sealing member 16 can be formed from fabric or non-fabric materialssuch as PET, PTFE, ePTFE, polyurethane, silicone, polyester, wire mesh,natural tissue (e.g., pericardium) and/or other suitable materialsconfigured to restrict and/or prevent blood-flow therethrough. In someembodiments, the sealing member can be formed from a generally flatstrip, folded lengthwise to form the inner and outer layers, and thenformed into a tube, such as by welding or stitching the ends together.In other embodiments, the sealing member 16 can be formed by weaving,knitting, or braiding the sealing member into a tubular shape. The bulgein the outer layer 36 can be formed, for example, by shape-setting thematerial to a desired configuration (e.g., as shown in FIGS. 1 and 2).The shape-setting of the outer layer can allow the outer layer to beself-expandable or induce radial expansion of the outer layer.Additionally or alternatively, the outer layer 36 can be self-expandableby including Nitinol threads in the outer layer.

In alternative embodiments, the inner layer 34 does not have anyopenings 42, but can be formed from a porous material that allows bloodto flow through the inner layer. For example, in some embodiments, theinner layer 34 can be formed from a relatively more porous material thanthe outer layer 36. In further alternative embodiments, the outer layer36 need not be configured to extend away from the outer surface of theframe and instead can have a shape that conforms to the outer surface ofthe frame. For example, the outer layer 36 can be generally tubular tocorrespond to the shape of the frame 12. In some embodiments, the outerlayer can be formed from a fabric having a pile layer (e.g., a velourfabric) having fibers or yarns forming looped or cut piles that helpseal against the surrounding tissue. Sealing members formed from suchfabrics are further described in U.S. Application No. 62/513,348, filedMay 31, 2017, which is incorporated herein by reference.

FIG. 6 shows a strip of fabric that can be used to form the sealingmember 16, according to one embodiment. As shown, a fabric strip cancomprise a center section 52 and first and second longitudinal edgeportions 54, 56 extending along opposing sides of the center section 52.The center section 52 can include three sets of one or more openings 42(e.g., three openings in each set in the illustrated embodiment). Theopenings 42 are positioned to correspond with the position of junctions50 below the commissures of the prosthetic valve. The first and secondlongitudinal edge portions 54, 56 can be folded over the center portion52 and secured to each other, such as with stitching, to form thesealing member. The longitudinal edge portions 54, 56 collectively formthe outer layer 36, while the center portion 52 forms the inner layer34.

FIGS. 7A and 7B are perspective views of exemplary tubular bodies thatcan be used to form a sealing member 16. Referring to FIG. 7A, a tubularbody 80 can comprise an upper portion 82 and a lower portion 84. Theupper portion 82 can include a radial bulge 86. The tubular body 80 canbe formed, for example, by three-dimensional weaving, knitting, orbraiding. The lower portion 84 can be folded or inverted into the upperportion 82 to form a sealing member having an outer layer formed by theupper portion 82 and an inner layer formed from the lower portion 84.

Referring to FIG. 7B, a tubular body 90 can comprise a cylindricalcentral portion 92, a flared upper portion 94, and a flared lowerportion 96. The tubular body 90 can be formed, for example, bythree-dimensional weaving, knitting, or braiding. The upper portion 94can folded or inverted over the lower portion 94 to form two layers of asealing member.

FIGS. 8-13 illustrate a technique for mounting the inflow edges 30 ofthe leaflets 20 to the frame 12, according to one embodiment. In theillustrated embodiment, a connecting skirt 100 is secured to a loweredge portion 102 (also referred to as a cusp edge portion) of eachleaflet. As best shown in FIG. 9, each connecting skirt 100 can comprisean elongated, generally rectangular body 104 formed with a plurality offlaps 106 a, 106 b formed along opposing longitudinal edges of the body104. The skirt 100 can comprise any suitable synthetic material (e.g.,PET) or natural tissue.

Referring to FIGS. 10 and 10A, to secure a connecting skirt 100 to aleaflet 20, the body 104 is folded along a central longitudinal foldbisecting the body to form folded portions 110 a, 110 b, which are thenplaced on opposite sides of the lower edge portion 102 of the leaflet 20such that the flaps 106 a are adjacent the outer surface of the leafletand the flaps 106 b are adjacent the inner surface of the leaflet. Asuture can then be used to form stitches 108 that extend through theopposing portions 110 a, 110 b of the body 104 and the lower edgeportion 102 of the leaflet and longitudinally along the length of thelower edge portion 102. FIG. 11A shows a flattened view of the leaflet20 with the skirt 100 folded around the lower edge portion 102 of theleaflet. FIG. 11B shows a flattened view of the leaflet 20 and the skirt100 after being secured to the leaflet with stitches 108.

Referring to FIGS. 12, 12A, and 12B, each pair of flaps 106 a, 106 b arefolded away from the leaflet 20 over a respective strut 22 of the frameand secured in place with stitches 112 that extend through the flaps 106a, 106 b along a stitching line outside of the frame 12. As best shownin FIG. 12B, the connecting skirt 100 mounts the leaflet to the frame 12such that the lower edge portion 102 extends radially inwardly at abouta 90-degree angle relative to the frame 12. This effectively moves thebending axis of the lower edge portion 102 inwardly away from the innersurface of the frame and toward the center of the frame.

As best shown in FIG. 8, each of the skirts 100 is secured to the framealong a diagonal line 116 extending along the curved surface of theframe defined by a diagonally extending row of struts 22 extending fromthe inflow end of the frame toward the outflow end. As such, the loweredge portion 102 of each leaflet is also positioned along a respectivediagonal line 116 defined by a respective diagonally extending row ofstruts 22. This advantageously reduces tension and the formation ofwrinkles in the leaflets 20.

The attachment along diagonal lines 116 also helps reduce the crimpingprofile of the prosthetic valve when the prosthetic valve is radiallycompressed to its delivery configuration. In particular, struts in acircumferentially extending row of struts of the frame are moved or benttoward each other during the crimping process while struts lying alongdiagonally extending lines 116 substantially retain their alignmentrelative to each other along lines 116 during the crimping process. Assuch, the connecting skirts 100 (which typically are formed fromnon-stretchable materials) do not inhibit movement or deformation of thestruts relative to each other. Also, since the cusp edge portions of theleaflets move with the connecting skirts during crimping, stretching ofthe leaflets along the cusp edge portions is prevented or at leastminimized.

FIG. 13A is a perspective view of the frame 12 and the leaflets 20supported in the frame shown in their mounted configuration with theconnecting skirts 100 removed for purposes of illustration. FIG. 13B isan enlarged, partial cross-sectional view of the frame and a leaflet. Ascan be seen, the lower edge portion 102 of the leaflet extendsperpendicularly or inversely parallel relative to the frame, creating agap G between the inner surface of the frame and the bending axis 114 ofthe leaflet 20. Advantageously, this helps prevent or at least minimizecontact of the outer surfaces of the leaflets with the frame and otherrelatively abrasive components, such as sutures, when the leaflets openduring valve operation, thereby inhibiting undesirable abrasion of theleaflets that occurs through contact with the frame. The enlarged spacedbetween the leaflet and the frame also can promote blood washing overthe leaflets at the bending axes of the leaflets.

Moreover, with known prosthetic valves, care must be taken to preventthe leaflets from extending through the open cells of the frame duringcrimping so as to prevent damage to the leaflets. For example, knowncrimping devices for prosthetic valves can include features oraccessories that press the leaflets away from the frame or shield theleaflets from extending through the frame cells during crimping. Incontrast, the skirts 100 assist in maintaining at least the inflowportions of the leaflets spaced from inner surface of the frame duringcrimping of the prosthetic valve to reduce the need for such speciallydesigned crimping accessories.

Further, the connecting skirts 100 (and the other connecting skirtsdescribed herein) can facilitate assembly of the prosthetic valvecompared to known assembly techniques. For example, the leaflets and theskirts can be assembled while the leaflets are in a flattenedconfiguration, prior to forming the tubular (annular) configuration thevalvular structure 14. Automated or semi-automated techniques can beused to suture the skirts to the leaflets. Also, once the valvularstructure is placed inside of the frame, the lower edge portions 102 ofthe leaflets can be secured to the frame with stitching that iscompletely outside of the frame 12. This can substantially reduceassembly time as the assembler does not have to thread the needle forforming stitches 112 in and out of the cells 24 of the frame.

As further shown in FIGS. 13A-13B, each leaflet 20 comprises opposingtabs 60. Each tab 60 can be secured to an adjacent tab 60 of an adjacentleaflet 20 to form a commissure that is secured to the frame 12. Eachtab 60 can be folded to form a radially extending layer 60 a and acircumferentially extending layer 60 b facing the frame. Methods formounting commissures to the frame are described in detail below and canbe incorporated into the prosthetic valve shown in FIGS. 13A-13B.

The tab layer 60 a can have an inclined edge 62 that extends radiallyinwardly from a location on the frame to a coaptation edge 64 of theleaflet. The inclined edge 62 also extends in an axial direction fromthe location on the frame to the coaptation edge 64. This places thecenter of the coaptation edge 64 (halfway between adjacent commisures)lower than the commissures and the attachment areas of the tabs 60 tothe frame. In other words, the commissures are located at differentlocations along the height of the frame than the centers of thecoaptation edges 64. This configuration is advantageous in that moreevenly distributes stress along the tabs 60 during valve cycling. Insome embodiments, the entire coaptation edge 64 of a leaflet is belowthe location where the commissures are attached to the frame, at leastwhen the leaflets are in the closed positions.

During valve cycling, the leaflets can articulate at the inner mostedges 66 of the tab layers 60 a, which helps space the leaflets awayfrom the frame during normal operation of the prosthetic valve. This isparticular advantageous in cases where the prosthetic valve is not fullyexpanded to its nominal size when implanted in a patient. As such, theprosthetic valve can be implanted in a wider range of patient annulussizes. Under relatively higher forces, such as when the prosthetic valveis radially compressed for delivery, the leaflets can splay apart fromeach other at the frame to relieve stress on the leaflets.

The commissures and the coaptation edges of the leaflets typically arerelatively bulky portions of leaflets and can inhibit full radialcompression of the prosthetic valve if they are at the same height alongframe. Another advantage of the commissure tabs 60 shown in FIGS.13A-13B is that the commissures and the coaptation edges are separatedfrom each other in the axial direction when prosthetic valve is radiallycompressed for delivery into a patient's body. Separating these portionsof the leaflets reduces the overall crimp profile of the prostheticvalve.

FIGS. 14 and 15A-15D show an alternative technique for mounting thelower edge portion 102 of a leaflet to the frame 12 using a connectingskirt 100. As shown in FIG. 14, slits 120 can be formed along thelowermost section of the edge portion 102 to facilitate folding of theedge portion during the assembly process. FIGS. 15A-15D show astep-by-step process for attaching the skirt 100 to the leaflet 20 andthen mounting the skirt to the frame.

Referring first to FIG. 15A, the skirt 100 is folded to form a firstlayer 124 and a second layer 126 and the folded skirt is placed alongthe upper surface of the leaflet 20. The edge portion 102 of the leafletis then wrapped around the folded edge of the skirt 100 to form a firstleaflet layer 128 and a second leaflet layer 130 sandwiching the layers124, 126 of the skirt. The layers 124, 126, 128, 130 can then be securedto each other with stitches 132 that extend through all four layers andlongitudinally along the length of the edge portion 102 of the leaflet.An advantage of folding the edge portion 102 of the leaflet is that theleaflet can better resist pull through of the stitches 132.

Referring to FIG. 15B, the second layer 126 of the skirt can then befolded around the two leaflet layers 128, 130 to form a third skirtlayer 134 adjacent the second leaflet layer 130 and a fourth skirt layer136 adjacent the first leaflet layer 128. Referring to FIG. 15C, thefirst skirt layer 124 can then be folded back over the third skirt layer134 to form a fifth skirt layer 138. The fourth skirt layer 136 canfolded back over itself to form a sixth skirt layer 140. All six skirtlayers and the two leaflet layers can be secured together with stitches142 extending through all eight layers and longitudinally along thelength of the edge portion 102 of the leaflet. In addition, the fifthand sixth layers 138, 140, respectively, can be secured together at alocation spaced radially outward from the leaflet 20 with stitches 144that extend through both layers and longitudinally along the length ofthe skirt 100.

The leaflet and skirt assembly can then be secured to the frame 12. Asshown in FIG. 15D, for example, layers 138, 140 of the skirt can beplaced below struts 22 of the frame and secured to the frame using, forexample, stitches 146 that extend around the struts and through thelayers 138, 140. Alternatively, the stitches 144 also can be wrappedaround the struts of the frame to mount the leaflet and skirt assembly,in lieu of or in addition to stitches 146. Thus, the lower edge portionof each leaflet extends along a diagonal line just below the line 116(FIG. 8) defined by the diagonal row of struts. Mounting the skirt belowthe diagonal row of struts 22 reduces motion of the skirt relative tothe frame and resulting abrasion of the skirt so as to protect againsttearing of the skirt during operation of the prosthetic valve.

In alternative embodiments, the skirt can be secured to the frame byplacing the fifth layer 138 over the struts and the sixth layer 140below the struts and securing those layers directly to each otheroutside of the frame (e.g., with sutures), similar to the way the skirtis secured to the frame in FIG. 12.

FIGS. 16-18 show alternative configurations for assembling a skirt 100and a leaflet 20 utilizing a folded leaflet edge portion. In FIG. 16,the skirt 100 is folded around the leaflet layers 128, 130 to form afirst skirt layer 150 below the leaflet layer 130, a second skirt layer152 between the leaflet layers 128, 130, and a third skirt layer 154above the leaflet layer 128. The leaflet and the skirt can be secured toeach other using stitches 156 that extend through the skirt layers 150,152, 154 and the leaflet layers 128, 130 and longitudinally along thelength of the leaflet edge portion 102. The configuration of FIG. 16utilizes less skirt layers than FIGS. 15A-15D and can permit a loweroverall crimp profile for the prosthetic valve 10. FIG. 17 is similar toFIG. 16 except that the first skirt layer 150 is folded inwardly to forman additional fourth skirt layer 158 between the first skirt layer 150and the lower surface of the leaflet 20. The fourth skirt layer 158 canhelp inhibit abrasion of the leaflet by positioning the edge of theskirt away from the articulating portion of the leaflet. FIG. 18utilizes the same configuration as the embodiment of FIGS. 15A-15Dexcept that in the embodiment of FIG. 18, stitches 160 extend throughskirt layers 124, 126, 134, 136 and leaflet layers 128, 130 but notskirt layers 138, 140. The leaflet and skirt assemblies shown in FIGS.16-18 can be secured to a frame 12 as previously described.

FIGS. 19-21 show another configuration for assembling a leaflet 20 and askirt 100. As shown in FIG. 19, the skirt 100 is folded around a loweredge portion 102 of the leaflet 20 to form first and second skirt layers170, 172 on the lower surface of the leaflet and third and fourth skirtlayers 174, 176 on the upper surface of the leaflet. The inner edges ofthe folded layers can be secured with stitches 178 extending through allfour layers 170, 172, 174, 176 and longitudinally along the length ofthe skirt and the leaflet. As shown in FIGS. 20 and 21, the skirt 100can then be mounted to the frame 12 by positioning the outer edges ofskirt layers 170, 176 below the diagonal row of struts 22 and securingthose layers to each other and the struts with stitches 180. Thestitches 180 extend through layers 170, 176 and around struts 22′ thatintersect with the struts 22 that form the diagonal row 116 of struts 22above the row.

FIG. 22 shows a similar configuration to that shown in FIGS. 19-21except that sections of the lower edge portion 102 of the leaflet extendthrough the cells of the frame. A first row of stitches 182 can be usedto secure the lower edge portion 102 of the leaflet and the inner edgesof the folded layers 170, 172, 174, 176. A second row of stitches 184can be used to secure the lower edge portion 102 of the leaflet and theouter edges of the folded layers 170, 172, 174, 176 at a locationoutside of the frame. The lower edge portion 102 of the leaflet can beformed with a series of slits 186 spaced along the length of the leafletcorresponding to location of struts 22 to allow the sections of thelower edge portion 102 to be extended through the cells of the frame.

FIG. 23 is a schematic representation of mounting the leaflets 20 to theframe utilizing connecting skirts 100. In the illustrated embodiment,the outer edges of the connecting skirts 100 can be secured to anannular inner skirt 190 (e.g., with sutures, an adhesive, or welding),which in turn can be secured to the struts of the frame (e.g., withsutures, an adhesive, or welding). Alternatively, the outer edges of theconnecting skirts 100 can be mounted directly to the struts of the framewithout an inner skirt 190, as previously described with respect to theembodiments in FIGS. 8-22. The inner edges of the connecting skirts 100can be connected to respective lower edge portions 102 of the leaflets(e.g., by sutures), which can be spaced from the inner surface of theinner skirt 190 and/or the frame 12 by the connecting skirts. Inparticular embodiments, for example, the width of a skirt 100 betweenthe lower edge of the respective leaflet 20 and the inner surface of theinner skirt 190 and/or the frame 12 can be about 1 mm to about 5 mm.

Forming the connecting skirts 100 from a fabric (e.g., PET) can promotetissue ingrowth and the formation or deposition of biologicalcomponents, such as fibrin and other blood components along the uppersurface of the connecting skirts during valve operation. Due to thematerial deposition of the skirts 100, they effectively become thickerand stiffer, thereby resisting flexing of the skirts during valvecycling. As a result, the normally closed position of the leaflets isdictated by diastolic pressure on the leaflets. During the systolicphase, the skirts 100 can remain substantially stationary, creating agap between the leaflets and the inner surface of the inner skirt 190and/or the frame 12 to protect against abrasion of the leaflets throughcontact with those components of the prosthetic valve.

FIGS. 24-25 show another configuration for mounting the lower,scalloped-shaped edge portions 102 of the leaflets to the frame 12. Asshown in FIG. 24, the lower edge portion 102 of a leaflet 20 can befolded upwardly toward the outflow end of the frame and against theinner surface of the frame to create a bending axis between the loweredge portion and the remaining portion of the leaflet that canarticulate toward and away from the frame during valve cycling. Thebending axis of the leaflets is therefore spaced inwardly from theframe, which can provide several advantages, including protectionagainst leaflet abrasion during valve cycling, reduction of stress alongthe lower edge of the leaflets during valve closure, improvedblood-washing of the leaflets (thus eliminating or at least minimizingearly calcification in those areas), and improved closing action of theleaflets. A reinforcing member 200, such as a wire, chord, sleeve,fabric or suture, can be placed along the upper surface of the leafletat the bending axis where the lower edge portion 102 intersects with thearticulating portion of the leaflet. In other embodiments, thereinforcing member 200 can be placed along the lower surface of theleaflet. The reinforcing suture 200 can comprise, for example, amulti-filament suture (e.g., an Ethibond suture).

The leaflet 20 can be coupled to the frame 12 using various techniquesor mechanisms. As shown in FIGS. 25A-25B, for example, the leaflet 20can be coupled to the frame 12 with a connecting skirt 202 having aninner longitudinal edge portion 204 and an outer longitudinal edgeportion 206. The inner edge portion 204 can be folded upwardly againstthe lower edge portion 102 of the leaflet. The outer edge portion 206can be folded downwardly against an outer skirt 210 (which can comprise,for example, the sealing member 16) mounted on the outside of the frame.The outer edge portion 206 can contact the outer skirt 210 through thecells of the frame at a location below a diagonal row of struts 22. Theconnecting skirt 202 can comprise two layers 202 a, 202 b of materialformed, for example, by folding the skirt lengthwise prior to assemblingthe skirt to the leaflet. Alternatively, the connecting skirt 202 cancomprise a single layer of material.

The inner edge portion 204 can be secured to the leaflet 20 withstitches 208 extending through the skirt 202, the leaflet 20, and thereinforcing suture 200 and longitudinally along the leaflet and theskirt. The outer edge portion 206 can be secured to the outer skirt 210via stitches 212 that extend through the connecting skirt 202 and theouter skirt 210 and longitudinally along the connecting skirt. As shownin FIG. 25B, the connecting skirt 202 also can be secured directly tothe frame via the stitches 212 or separate stitches that extend throughthe outer edge portion 206 of the skirt 202 and around junctions 50 ofthe frame where two struts intersect. The connecting skirt can be leftunattached to apices 216 formed by the intersection of respective pairsof struts 22 at the inflow end of the frame.

The row of stitches 212 desirably extends above the apices 216 as shownto prevent the leaflets from protruding below the inflow end of theframe so as to protect against the leaflets contacting adjacent nativetissue, such as calcium nodes, prior to or during deployment of theprosthetic valve 10. Having the lower edge portions 102 of the leafletsfolded upwardly away from the connecting skirt 202 and toward theoutflow end of the frame can minimize the amount of overlapping layersof material of the skirt 202, the leaflet 20 and the frame 12 so as toreduce the overall crimp profile of the prosthetic valve.

FIG. 26 shows an alternative configuration for mounting the leaflets 20to the frame using the connecting skirts 202. The embodiment of FIG. 26can be the same as the embodiment of FIGS. 24 and 25 except that theouter edge portion 206 of the connecting skirt 202 extends between alower edge portion of an upper outer skirt 218 and an upper edge portionof a lower outer skirt 220. The connecting skirt 202, the upper outerskirt 218, and the lower outer skirt 220 can be secured to each otherwith stitches 222 extending through all three layers of material.

FIG. 27 shows another alternative configuration for mounting theleaflets 20 to the frame using the connecting skirts 202. The embodimentof FIG. 27 can be the same as the embodiment of FIGS. 24 and 25 exceptthat the outer edge portion 206 of the connecting skirt 202 can befolded upwardly toward the outflow end of the frame. The outer edgeportion 206 can be secured to the outer skirt 210 with stitches 212.

FIGS. 28 and 29 illustrate in greater detail different ways of stitchingthe inner edge portion 204 of the connecting skirt 202 to the lower edgeportion 102 of a leaflet 20. In FIG. 28, the stitches 208 extend throughthe inner skirt layer 202 b but not the outer skirt layer 202 a. In FIG.29, the stitches 208 extend through both skirt layers 202 a, 202 b.

FIG. 30 shows another configuration for mounting the lower edge portions102 of the leaflets to the frame 12. As shown in FIG. 30, the lower edgeportion 102 of a leaflet can be coupled to the frame 12 with aconnecting skirt 230 having an upper edge portion 232 and a lower edgeportion 234. The upper edge portion 232 can be secured to an outer skirt210 at a location above a diagonal row of struts 22 via stitches 236that extend through the outer skirt and the connecting skirt. The loweredge portion 234 of the connecting skirt can be secured to the outerskirt at a location below the diagonal row of struts 22 via stitches 238that extend through the outer skirt and the connecting skirt. Anintermediate portion of the connecting skirt (between the upper andlower edge portions 232, 234) can extend over the diagonal row ofstruts.

As shown in FIG. 30, the spacing between the row of struts and thestitching 236 desirably is greater than the spacing between the row ofstruts and the stitching 238, which can increase the contact angle ofthe skirt and the struts 22. The encircled area 240 in FIG. 30represents the contact area where contact between the connecting skirt230 and the frame 12 occurs, or where a majority of the contact betweenthe connecting skirt and the frame occurs. Under systole, the angle ofthe skirt 230 relative to a transverse axis of the frame (the transverseaxis being perpendicular to a longitudinal axis of the frame) at thecontact area 240 is about 60 to 90 degrees, or more preferably about 70to 90 degrees, or even more preferably about 80 to 90 degrees.Increasing the contact angle of the skirt can reduce bending stresses inthe skirt during valve cycling to improve durability of the skirt.Further, the connecting skirt 230 can be sized or configured such thatduring diastole, the connecting skirt can move slightly radiallyinwardly under blood pressure and separate from the skirt 230 from thestruts 22 so as to remove or minimize contact between the skirt andstruts.

FIG. 31 shows another configuration for mounting the lower edge portions102 of the leaflets to the frame 12 with connecting skirts 230 similarto the embodiment of FIG. 30 except that the upper edge portion 232 ofthe connecting skirt is secured to an upper diagonally extending row ofstruts 22 a and the lower edge portion 234 of the connecting skirt issecured to a lower diagonally extending row of struts 22 b. In thismanner, the lower edge portion 102 of the leaflet can be secured to theconnecting skirt 230 between the upper and lower rows of struts. Theupper edge portion 232 of the connecting skirt can be at least partiallywrapped around the struts 22 a of the upper row and secured in place byloop stitches 250 extending through the skirt and around the struts 22a. The lower edge portion 234 of the connecting skirt can be at leastpartially wrapped around the struts 22 b of the lower row and secured inplace by loop stitches 252 extending through the skirt and around thestruts 22 b. Attaching the connecting skirt 230 to two adjacentdiagonally extending rows of struts in the manner shown in FIG. 31 canprevent or at least minimize relative motion between the connectingskirt and the frame to improve durability of the skirt.

FIG. 32 shows another configuration for mounting the lower edge portions102 of the leaflets to the frame 12 without any connecting skirts. Inthe embodiment of FIG. 32, the lower edge portion 102 of a leaflet 20can be folded upwardly against a diagonal row of struts 22 and securedin place with loop stitches 254 extending around the struts 22 andthrough the leaflet edge portion 102 at a first location, through thereinforcing suture 200, and through the leaflet edge portion 102 at asecond location. Placing the folded edge portion 102 of the leafletparallel to the inner surfaces of the struts can minimize wear of theleaflets due to motion of the leaflets relative to the frame. Theelimination of the skirts in this embodiment can reduce the overallcrimp profile of the prosthetic valve and can achieve a tighterconnection between the leaflets and the frame to reduce relative motionbetween these two components.

FIGS. 33-37 show a technique for mounting the commissures of a valvularstructure to a frame, such as the commissures 32 to the frame 12,according to one embodiment. FIG. 33 shows a leaflet 300 having a loweredge portion 302 that can be mounted to the frame 12 using any of thepreviously described embodiments. The lower edge portion 302 terminatesat its upper ends at two laterally projecting integral lower tabs 304.Projecting from the upper corners of the leaflet 300 are integral uppertabs 306 (also referred to as commissure tabs). The upper tabs 306 canbe spaced from the lower tabs 304 by side edges 338 defining laterallyextending gaps or recesses in the leaflet.

To assemble the commissure, each upper tab 306 is folded along ahorizontal fold line 308 to form first and second tab layers 306 a, 306b, as shown in FIG. 33 (see also FIG. 37). A first vertically extendingreinforcing member 310 can be placed against the first tab layer 306 aadjacent its inner edge. A second vertically extending reinforcingmember 312 can be placed against the second tab layer 306 b opposite thefirst reinforcing member 310. The first and second tab layers 306 a, 306b can be secured to each other with stitching 314 that extends throughthe first and second tab layers 306 a, 306 b and the first and secondreinforcing members 310, 312.

The first and second tab layers 306 a, 306 b can then be foldedlengthwise along a vertical fold line as shown in FIG. 35 to form anouter folded portion 316 and an inner folded portion 318 that extendsradially inwardly from the outer folded portion 316. A third verticallyextending reinforcing member 320 can be placed against the first foldedlayer 306 a of the outer folded portion 316 and a commissure attachmentmember 322 can be placed against the second folded layer 306 b of theouter folded portion 316. The outer folded portion 316 can be secured tothe commissure attachment member 322 with stitches 324 that extendthrough the third reinforcing member 320, the first and second tablayers 306 a, 306 b, and the commissure attachment member 322. The outeredges of the first and second tab layers 306 a, 306 b can be furthersecured to the commissure attachment member 322 with stitches 326. Theupper tab 306 of a second leaflet 300 can be assembled in the samemanner with respective reinforcing members and attached to thecommissure attachment member 322 adjacent the first leaflet to form acommissure 328 as shown in FIG. 37. The commissure attachment member 322can then be secured to the struts of the frame (see, e.g., FIG. 65), asfurther described below.

The folded tab layers 306 a, 306 b, reinforced by the first and secondreinforcing members 310, 312, can be more resistant to bending, orarticulating, than the portions 330 of the leaflets that are radiallyinward of the tab layers. This causes the leaflets 300 to articulateprimarily at inner edges 332 of the folded layers 306 a in response toblood flowing through the prosthetic valve during operation of theprosthetic valve in the body, as opposed to articulating aboutrespective axes on or adjacent the metal struts of the frame. Becausethe leaflets articulate at a location spaced radially inwardly from theframe 12, the leaflets can avoid contact with and damage from the frame.This is particularly advantageous in cases where the prosthetic valve isnot fully expanded to its nominal size when implanted in a patient'sbody. As such, the prosthetic valve can be implanted in a wider range ofpatient annulus sizes.

Under high forces, the folded tab layers 306 a, 306 b of adjacentleaflets can splay apart from each other about respective axes 334 (FIG.37) adjacent to the frame 12, with each inner folded portion 318 foldingout against the respective outer folded portion 316. For example, thiscan occur when the prosthetic valve 10 is compressed and mounted onto ashaft of a delivery apparatus, allowing for a smaller crimped diameter.The folded tab layers can also splay apart about their axes 334 when theballoon of the balloon catheter is inflated during expansion of theprosthetic valve, which can relieve some of the pressure on thecommissures caused by the balloon and so the commissures are not damagedduring expansion.

When the leaflets 300 are mounted to the frame, the lower tabs 304 ofeach leaflet can be folded downwardly against the cusp edge portion 302and held in place, such as with sutures. The folded lower tabs 304 helpreinforce the connection between the cusp edge portions 302 of theleaflets and the frame along the upper sections of the cusp edgeportions adjacent the commissures. The folded lower tabs 304 also movethe bending axes of the upper sections of the cusp edge portionsinwardly and away from the inner surface of the frame to prevent orminimize contact between the leaflets and the frame in the areas belowthe commissures.

The side edges 338 between the lower and upper tabs 304, 306 can be leftunattached to the frame of the prosthetic valve (see FIG. 1C). Theunattached side edges 338 provide several advantages, including reducingstress in the leaflets, by allowing greater elongation or stretching ofthe leaflets in the axial direction when the prosthetic valve iscompressed from the radial expanded state to the radial compressed stateduring the crimping process and by allowing greater elongation orstretching of the leaflets in the radial direction when the prostheticvalve is expanded to its radial expanded state. The unattached sideedges 338 also allow blood to flow in the space between a pair of sideedges 338 of adjacent leaflets and the inner surface of the frame toreduce stagnant blood flow and thrombosis. During diastole, the adjacentside edges 338 can coapt with each other and prevent retrograde bloodfrom flowing between the side edges 338. During systole, the adjacentside edges 338 can separate from each other and allow antegrade blood toflow between side edges 338 and help wash away blood from the areasunderneath the commissures.

The reinforcing members 310, 312, 320 desirably comprise relatively softand flexible, non-metallic materials. For example, the reinforcingmembers can comprise multi-filament sutures (e.g., Ethibond sutures) orstrips of synthetic material, such as fabric (e.g., PET) or non-fabricmaterial (e.g., silicone or polyurethane), or natural tissue (e.g.,pericardium). The commissure attachment member 322 similarly cancomprise a soft and flexible, non-metallic material, such as strips ofsynthetic material, such as fabric (e.g., PET) or non-fabric material(e.g., silicone or polyurethane), or natural tissue (e.g., pericardium).Hence, in the illustrated embodiment, the commissure 328 does notinclude metallic components or other materials having similar rigidity.The absence of such materials can reduce abrasion and wear of theleaflet material and reduce the overall crimp profile of the prostheticvalve.

FIG. 38 shows a modification of the embodiment shown in FIG. 37. Theembodiment of FIG. 38 can be same as that shown in FIG. 37 except thatthe pair of folded layers 306 a, 306 b of adjacent leaflets 300 can besecured to each other with a suture 336 that extends through thereinforcing members 310, 312 and the tab layers 306 a, 306 b of eachleaflet 300. Securing the leaflets together can reinforce the bendingaxes of the articulating portions 330 of the leaflets during normalvalve operation.

FIG. 39 shows an alternative embodiment of a leaflet 340, which issimilar to the leaflet 300, except that the leaflet 340 includes uppertabs 340 that project laterally a greater distance than the upper tabs306. Each upper tab 340 can be folded widthwise along a respectivevertical fold line 342 to form two folded tab layers that are pairedwith folded tab layers of an adjacent leaflet to form a commissure aspreviously described.

FIGS. 40-46 show another embodiment of a leaflet and a method forforming a commissure from two leaflets. As shown in FIG. 40, a leaflet400 comprises a lower edge portion 402 terminating at lower tabs 404,upper tabs 406 (also referred to as commissure tabs) spaced from thelower tabs 404 by gaps 408. The lower tabs 404 can be folded downwardlyagainst the lower edge portion 402 to reinforce those areas of theleaflet and to move the bending axes of the upper sections of the edgeportions 402 (the portions just below the commissures) inwardly awayfrom the inner surface of the frame, as previously described.

Each upper tab 406 includes a lower tab portion 410, an upper tabportion 412 extending from the lower tab portion, and a side tab portion414 extending laterally inwardly from the upper tab portion. To form acommissure, a reinforcement member 418 (e.g., a multi-filament suture ora strip of fabric) can be placed vertically along the upper tab portion412 in the manner shown in FIG. 41. The side tab portion 414 can then befolded along a fold line 416 against the upper tab portion 412 as shownin FIGS. 41-42. The dual layer of the side tab portion 414 and the uppertab portion 412 can then be folded along horizontal fold line 420against the lower tab portion 410, as depicted in FIGS. 42-43.

As shown in FIG. 44, a commissure attachment member 422 can then beplaced against the rear (outer) surface of the lower tab portion 410 andsecured to the upper tab 406 with stitching 424 that extends through theupper tab portion 412, reinforcement member 418, the side tab portion414, the lower tab portion 410, and the commissure attachment member422. The three layers formed by the lower tab portion 410, the upper tabportion 414, and the side tab portion 414 can then be folded into anL-shape to form an outer folded portion 426 adjacent the commissureattachment member 422 and an inner folded portion 428 extending radiallyinwardly from the outer folded portion as shown in FIG. 46. As shown inFIG. 46, the tab layers of the outer folded portion 426 can be furthersecured to the commissure attachment member 422 with stitches 432. Theupper tab 406 of another leaflet can be assembled in the same manner andsecured to the same commissure attachment member 422 to form acommissure 430 as shown in FIGS. 45-46.

As described above, the stitches 424 can extend through each layerformed by the lower tab portion 410, the upper tab portion 414, and theside tab portion 414. As shown in FIG. 46, the stitches 424 from eachcommissure tab 406 can extend diagonally toward each other to compressthe folded commissure tabs 406 against each other and the commissureattachment member 422. In alternative embodiments, the stitches 424 canbe placed through the reinforcement member 418, the side tab portion 414and the lower tab portion 410 prior to folding the upper tab portion andthe side tab portion along fold line 420. In this manner, the stitches424 need not extend through the upper tab portion 412, as depicted inFIG. 46. In some embodiments, another reinforcement member 438 can beplaced against the outer surface of the commissure reinforcement member422 (FIG. 46). The stitches 424 from each commissure tab 406 can extendthrough the reinforcement member 438 at the same location as shown or atspaced apart locations.

The commissure 430 can function similar to the commissure 328 describedabove. Thus, during normal valve cycling, the leaflets 400 canarticulate about respective axes at the inner ends 434 of the tab layers412. The compression of the folded commissure tabs 406 by stitches 424helps maintain the normal bending axes of the leaflets 400 away from theframe. During valve deployment, the leaflets can splay apart from eachother at an axis 436 adjacent the commissure attachment member 422.

FIG. 47 shows an alternative configuration for forming a commissure. Theembodiment of FIG. 47 is similar to the embodiment of FIGS. 33-37 exceptthat a vertical reinforcement member 344 can be placed between twolayers of the commissure tab of the leaflet. The commissure can beformed by placing the reinforcement member 344 on tab portion 306 aprior to folding tab portion 306 a along fold line 308. After foldingthe commissure tab 306, the folded layers 306 a, 306 b can be secured tothe commissure attachment member 322 with stitches 346 that extendthrough the reinforcement member 344, both tab layers 306 a, 306 b, andthe commissure attachment member 322.

FIG. 48 shows an alternative configuration for forming a commissuresimilar to FIG. 46, except that each folded commissure tab 406 issecured to a separate reinforcing member 438 (one of which is shown inFIG. 48). Also, stitches 440 can secure the side tab portion 412 to thereinforcing member 418.

FIGS. 49-54 show another embodiment of a leaflet and a method forforming a commissure 32 from two leaflets. As shown in FIG. 49, aleaflet 500 comprises a lower edge portion 502 terminating at lower tabs504, upper tabs 506 (also referred to as commissure tabs) spaced fromthe lower tabs 504 by gaps 508. The lower tabs 504 can be foldeddownwardly against the lower edge portion 502 to reinforce those areasof the leaflet and to move the bending axes of the upper sections of theedge portions 502 (the portions just below the commissures) inwardlyaway from the inner surface of the frame, as previously described.

Each commissure tab 506 includes a lower tab portion 510 and an uppertab portion 512. To form a commissure, the upper tab portion 512 isfolded along fold line 514 against the lower tab portion 510. The duallayer comprising tab portions 510, 512 can then be folded along avertical fold line 516 to form a first layer 518, a second layer 520, athird layer 522, and a fourth layer 524 from each commissure tab 506, asdepicted in FIGS. 50-52. A reinforcement member 526, such as strip offabric (e.g., PET), can be positioned between the second layer 520 andthe third layer 522.

The commissure tab 506 of another leaflet 500 is folded in the samemanner and placed against the folded commissure tab of the first leafletwithin a commissure attachment member 528. The commissure attachmentmember 528 can be folded as shown in FIG. 50 to form a central outerportion 530, outer end portions 532, and side portions 534, eachcomprising first and second layers 534 a, 534 b of material extendingfrom respective ends of an end portion 532 and the central outer portion530. The side portions 534 can be placed against respective fourthlayers 524 of the commissure tabs.

As shown in FIG. 50, the layers 534 a, 534 b of each side portion 534can be secured to each other with stitching 536. Each side portion 534can be secured to a commissure tab 506 with stitching 538 extendingthrough a respective reinforcing member 526, respective third and fourthlayers 522, 524, and both layers of a respective side portion 534. Thecommissure attachment member 528 can be secured to the struts 22 of aframe 12 with sutures or other techniques or mechanisms.

FIG. 51 shows another way of securing the folded commissure tabs 506 tothe commissure attachment member 530. As shown in FIG. 51, for eachcommissure tab, a row of laterally extending stitches 540 can be used tosecure the inner end portions of the layers 534 a, 534 b of the sideportion, the third and fourth layers 522, 524, and the reinforcingmember 526. A diagonally extending row of stitches 524 can be used tosecure the reinforcing member 526, the third and fourth layers 522, 524,and the rear end portions of layers 534 a, 534 b of the side portion.

As shown in FIG. 52-53, each commissure 32 can include an inner sleeve544 and an outer support member 546. The inner sleeve 544 can comprisefirst and second portions 544 a, 544 b, each of which extends around theouter side as well as the upper and lower portions of a respectivefolded commissure tab 506. The adjacent upper ends 548 of the first andsecond portions 544 a, 544 b can be secured to each other (e.g., withsutures) at the center of the commissure 32. The adjacent lower ends ofthe first and second portions 544 a, 544 b can be secured to each other(e.g., with sutures) in a similar manner at the center of the commissure32. Each of the side portions 534 of the commissure attachment member528 can be secured to one of the first and second portions 544 a, 544 bof the inner sleeve (e.g., with sutures). The outer support member 546can be secured to the central outer portion 530 and/or the end portions532 of the commissure attachment member 528 (e.g., with sutures).

As shown in FIG. 54, at least a portion of the outer support member 546can be positioned outside of the frame 12. The outer support member 546can be secured (e.g., with sutures) to each strut 22 of a set of strutsforming a cell of the frame. In the illustrated embodiment, for example,the outer support member 546 can be sutured to each strut of adiamond-shaped cell comprised of four struts 22. The inner sleeve 544and the outer support member 546 can comprise any suitable relativelyflexible and soft material as previously described for the reinforcementmembers and the commissure attachment members of the embodimentsdescribed above. In particular embodiments, the inner sleeve 544 and theouter support member 546 comprise PET fabric.

FIG. 55 shows a modification of the commissure 32 shown in FIGS. 52-54.The embodiment of FIG. 55 can be the same as the embodiment of FIGS.52-54, except that the former includes reinforcing members 554 in theform of multi-filament sutures positioned between the second and thirdlayers 520, 522 of each commissure tab 506.

FIG. 56 shows an alternative embodiment for forming a commissure fromtwo leaflets 300. The commissure tabs 306 can be folded in a mannersimilar to that described above for the embodiment of FIGS. 33-37. Asshown, a reinforcement member 350 (e.g., strips of PET fabric or othermaterial) can be placed at the fold of each layer 306 a. A commissureattachment member 352 can be placed against the outer folded portions316 of each layer 306 b and folded in the manner shown in FIG. 56 tocreate three layers of material 352 a, 352 b, 352 c at each layer 306 b.For each commissure tab 306, stitches 354 can be used to secure thereinforcement member 350, layers 306 a, 306 b and the three foldedlayers of the commissure attachment member 352.

FIGS. 57-58 show a prosthetic valve 600, according to anotherembodiment. The prosthetic valve 600 can be similar to the prostheticvalve 10 described above except for the configuration of the sealingmember. The prosthetic valve 600 in the illustrated embodiment comprisesa sealing member 602 comprising an inner portion or layer 604 and anouter portion or layer 606. The inner layer 604 is mounted inside of theframe 12 and comprises three triangular shaped portions 608. FIG. 59shows the sealing member 602 in a flattened configuration prior toattachment to the frame. The half triangular portions at each end of thesealing member form a triangular portion 608 when the sealing member isformed into a tubular or annular shape with the ends connected to eachother.

The upper edge portion 610 of the inner layer is shaped to correspond tothe shape of the lower edge portions 102 of the leaflets 20. The loweredge portions 102 of the leaflets 20 can be connected directly to theupper edge portion 610 of the inner layer 602 (e.g., with sutures),using connecting skirts (e.g., any of the connecting skirts describedherein, such as skirts 100) or other mounting techniques describedherein. The upper edge portion 610 of the inner layer 602 can be securedto the struts 22 of the frame 12, such as with the sutures used toconnect the inner layer to the leaflets or with separate sutures thatextend around the struts 22 and through the inner layer. The inner layer604 functions to prevent antegrade blood from flowing outwardly throughthe cells of the frame below the inflow edges of the leaflets.

The outer layer 606 can be wrapped around the inflow end 26 of the frameand secured (e.g., with sutures) along its upper edge portion 612 to thestruts 22 on the outside of the frame 12. Individual sutures can be usedto secure the outer layer 606 at circumferentially spaced apartlocations to the apices at the inflow end 26 of the frame.

The outer layer 606 can be shaped or configured to extend radiallyoutwardly from the frame when the prosthetic valve is radially expandedto its functional size to create a space 614 between the frame and theouter layer 606. Upon deployment in a patient's body, retrograde bloodcan flow over the outer surface of the leaflets 20, through the cells ofthe frame, and into the space 614 inside of the outer layer 606 tofacilitate creation of a seal against the surrounding tissue. Theabsence of material inside of the frame facing the movable portions ofthe leaflets 20 can reduce the overall crimp profile of the prostheticvalve and can inhibit abrasion of the leaflets 20, especially in caseswhere the prosthetic valve is not fully expanded to its nominal size.Consequently, this can allow the prosthetic valve to be implanted in awider range of patient annulus sizes.

The sealing member 602 can be formed from the same materials and usingthe same techniques as described above for the sealing member 16.

FIGS. 60-61 show a prosthetic valve 700, according to anotherembodiment. The prosthetic valve 700 can similar to the prosthetic valve10 described above except for the configuration of the sealing member.The prosthetic valve 700 in the illustrated embodiment comprises asealing member 702 comprising an inner portion or layer 704 and an outerportion or layer 706. The inner layer 704 is mounted outside of theframe 12 and comprises three triangular shaped portions 708. Inparticular embodiments, the triangular shaped portions 708 are connectedonly by a thin strip 705.

FIG. 62 shows the sealing member 702 prior to assembling it on the frame12 and folded into its final shape. When mounting the sealing member 702on the frame 12, the sealing member can first be placed on the frame asshown in FIG. 63 such that the inflow end portion of the inner layer 704is adjacent the inflow end 26 of the frame. The triangular portions 708are shaped to correspond to the shape of the lower edge portions 102 ofthe leaflets 20 and cover the openings in the frame between adjacentedge portions 102 underneath each commissure. By virtue of the shape ofthe triangular portions 708, the inner layer 704 does not cover theportions of the frame facing the outflow surfaces of the leaflets.

The lower edge portions 102 of the leaflets 20 can be connected directlyto the upper edge portion 710 of the inner layer 704 (e.g., withsutures), using connecting skirts (e.g., any of the connecting skirtsdescribed herein, such as skirts 100) or other mounting techniquesdescribed herein. The inner layer 704 functions to prevent antegradeblood from flowing outwardly through the cells of the frame below theinflow edges of the leaflets.

The outer layer 706 can then be folded over the inner layer 704 towardthe inflow end 26 of the frame such that the upper end of the pre-foldedouter layer becomes the lower (inflow) end of the outer layer and liesadjacent the inflow end 26 of the frame, as shown in FIG. 60. Foldingthe outer layer over the inner layer inverts the outer layer such thatthe inner surface of the pre-folded outer layer becomes the outersurface of the outer layer and the outer surface of the pre-folded outerlayer becomes the inner surface of the outer layer in its folded,assembled state. FIG. 64 shows the sealing member 702 in its final,folded state apart from the rest of the prosthetic valve for purposes ofillustration. After folding the outer layer 706, the inflow and/oroutflow ends of the outer layer can be secured to the struts 22 of theframe (e.g., with sutures).

The sealing member 702 can be formed from the same materials and usingthe same techniques as described above for the sealing member 16. Inalternative embodiments, the inner layer 704 and the outer layer 706 canbe separate pieces of material, which can be secured to each other(e.g., with sutures) at their inflow ends and/or outflow ends.

Similar to the embodiment of FIGS. 57-59, the outer layer 706 can beshaped or configured to extend radially outwardly from the frame whenthe prosthetic valve is radially expanded to its functional size tocreate a space 714 between the frame and the outer layer 706. Upondeployment in a patient's body, retrograde blood can flow over theoutflow surface 70 of the leaflets 20, through the cells of the frame,and into the space 714 inside of the outer layer 706 in the direction ofarrows 716 to facilitate creation of a seal against the surroundingtissue. The triangular shaped portions 708 prevent antegrade blood fromflowing through the frame at locations between the cusp edge portions102 of the leaflets. The absence of material inside of the frame canreduce the overall crimp profile of the prosthetic valve and can inhibitabrasion of the leaflets 20, especially in cases where the prostheticvalve is not fully expanded to its nominal size. Consequently, this canallow the prosthetic valve to be implanted in a wider range of patientannulus sizes.

FIG. 65 shows a prosthetic valve 800, according to another embodiment.The prosthetic valve 800 can include a sealing member 802 mounted to theframe 12 as described above in connection with the embodiment of FIGS.60-63. The prosthetic valve 800 can include leaflets 814 connected toeach other at their outflow ends to form commissures 810 that aremounted to the cells at the outflow end of the frame. The commissures810 can be formed by folding commissure tabs of the leaflets andsecuring them to a commissure attachment member 812. Each commissureattachment member 812 can be sutured to four struts 22 that define aclosed cell 24 of the frame. A method for forming the commissures 810and mounting them to a cell 24 via the commissure attachment members 812is described in detail below.

FIG. 68 show the sealing member 802 apart from the other components ofthe prosthetic valve. The sealing member 802 comprises an inner layer804 and an outer layer 806. The inner layer 804 can comprise a pluralityof triangular-shaped portions 808. The sealing member 802 can have thesame or similar construction as the sealing member 702, except that thetriangular-shaped portions 808 are not connected to each other at theirlower (inflow) ends. The sealing member 802 can be mounted to frame 12as described above in connection with sealing member 702.

Referring to FIGS. 74-78, a method for forming the commissures 810 andmounting them to the frame 12 will be described. As best shown in FIG.75, each leaflet 814 has a lower or cusp edge portion 816 that can bemounted to the frame 12 using any of the previously describedembodiments. The lower edge portion 816 terminates at its upper ends attwo laterally projecting integral lower tabs 818. Projecting from theupper corners of the leaflet 814 are integral upper tabs 820 (alsoreferred to as commissure tabs). The upper tabs 820 can be spaced fromthe lower tabs 818 by side edges 819 forming laterally extending gaps orrecesses 820 in the leaflet.

As shown in FIG. 75B, each upper tab 820 is folded along a fold line 814to form first and second tab layers 820 a, 820 b, similar to thetechnique described above for leaflet 300 shown in FIGS. 33-37. Theupper tab 820 is secured to a commissure attachment member 812, alongwith the upper tab 820 of an adjacent leaflet to form a commissure 810,as further described below. FIG. 76 shows a commissure attachment member812 in a flattened configuration prior to folding and attachment to theleaflets. Each commissure attachment member 812 in the illustratedconfiguration comprises first and second side portion 828 a, 828 bprojecting laterally from a central portion 830. As shown, the outerperipheral edges 832 of the side portions 828 a, 828 b can be shaped tocorrespond to one half of a diamond-shaped cell 24 of the frame 12 tofacilitate mounting of the commissure attachment member 812 to thestruts 22 of the frame 12, as further described below.

Referring to FIGS. 77-78, after the upper tab 820 of a leaflet 814 isfolded, a vertical reinforcement 826 can be secured to the inner surfaceof tab layer 820 a, such as with stitching. The folded tab layers 820 a,820 b can be secured to a side portion 828 a or 828 b of the commissureattachment member 812. The folded tab layers also can be folded along avertical fold line at the reinforcement 826 in an L-shape such that thetab layer 820 b forms a first circumferentially extending layer 834 aand a first radially extending layer 834 b that is generallyperpendicular to the layer 834 a and the tab layer 820 a forms a secondinner circumferentially extending layer 836 a and a radially extendinglayer 836 b that is generally perpendicular to the layer 836 a. Anotherupper tab 820 of an adjacent leaflet 814 can be similarly folded andsecured to the other side portion 828 a or 828 b of the commissureattachment member 812.

The commissure attachment member 812 can be folded as shown in FIG. 78to form an inner layer 838 and two intermediate layers 840 and two outerlayers 842. Each folded upper tab 820 can be secured to the inner layer383 and an intermediate layer 840 with stitching 844. In the illustratedembodiment, stitching 844 is shown extending through the reinforcementmember 826, a layer 836 a, a layer 834 a, layer 838, and a layer 840.However, during the assembly process, multiple stitches can be employedto secure each layer to an adjacent layer as each folded is created. Forexample, layers 834 a, 836 a can be secured to each other and areinforcement member 826 with separate stitching, and additionalstitching can then be used to secure the leaflet layers to the innerlayer 838 of the commissure attachment member 812, and further stitchingcan be used to secure an intermediate layer 840 to the inner layer 838.As best shown in FIG. 78, the commissure attachment member 812 can befolded to leave a small gap 846 between the outer layers 842.

The outer layers 842 can be secured to the frame 12, such as by suturingthe outer peripheral edges 832 to struts 22 with stitching 848. Asmentioned above, the outer peripheral edges 832 of the commissureattachment member 812 can generally correspond to the shape of a closedcell of the frame 12. For example, as shown in FIG. 71, the frame 12 inthe illustrated embodiment comprises a plurality of generallydiamond-shaped cells 24, each of which is formed by struts 22 a, 22 b,22 c, and 22 d. Stitching 848 can be used to suture the outer peripheraledges 832 of the commissure attachment member 812 to struts 22 a, 22 b,22 c, 22 d forming a closed cell 24. The commissure attachment member812 can further include an upper tab 850 and a lower tab 852 projectingfrom the upper and lower edges of the central portion (FIG. 76).Stitching 848 can also be used suture the upper tab 850 an apex 854formed by the intersection of struts 22 a, 22 c and to suture the lowertab 852 to a junction 856 formed by the intersection of struts 22 b, 22d.

The inflow or cusp edge portions 816 of the leaflets 814 can be securedto the frame 12 using a plurality of connecting skirts 860 (FIG. 70),which can be formed of the same materials as described above for theconnecting skirt 100 (e.g., PET fabric). In the illustrated embodiment,a single connecting skirt 860 is provided for the cusp edge portion 816of each leaflet 814 and is sized to extend along the entire length of acusp edge portion 816 to locations just below the lower tabs 818 of theleaflet 814. FIG. 75B shows a connecting skirt 860 placed along the cuspedge portion 816 of a leaflet 814 prior to being attached to the leafletwith sutures. The connecting skirt 860 can include a central portion 860a sized to extend over the central lower edge portion and two sideportions 860 b sized to extend over the angled side edge portionsextending from the lower central portion to the lower tabs 818. Theconnecting skirt 860 can be formed with slits 862 partially separatingthe side portions 860 b from the central portion 860 a to facilitatealignment of the skirt along the cusp edge portion as shown in FIG. 75B.

In alternative embodiments, plural connecting skirts can be provided forthe cusp edge portion of each leaflet (e.g., the central portion 860 aand the side portions 860 b can be separate pieces of fabric). Inanother embodiment, a single connecting skirt can be used to secure allof the leaflets to the frame; i.e., a single connecting skirt can besized to extend along the cusp edge portions of all of the leaflets.

Prior to attaching the leaflets to the frame, a connecting skirt 860 canbe attached to the cusp edge portion of each leaflet. As shown in FIG.69, a connecting skirt 860 can be folded lengthwise to form two foldlayers 864 a, 864 b and placed against the inflow surface of the cuspedge portion 816. A reinforcing member or chord 866 (e.g., an Ethibondsuture) can be placed against the outflow surface of the cusp edgeportion opposite the connecting skirt 860. The reinforcing member 866and the fold layers 864 a, 864 b can be sutured to each other and to thecusp edge portion 816 with stitching 868, which can be a single sutureor multiple sutures extending through one or more layers of material.

When suturing the reinforcing chord 866 to the leaflet 814, the lowertabs 818 can be folded downwardly against the cusp edge portion 816 (seeFIG. 75B) and the reinforcing chord 866 can be placed over the foldedlower tab 818. The upper ends of the connecting skirt 860 can be sizedto extend over the folded lower tabs 818. Stitching 868 can be used tosecure the reinforcing chord 866 in place against the folded lower tab818. In particular embodiments, as best shown in FIG. 67, thereinforcing chord 866 can extend along the folded lower tab 818 of oneleaflet 814, through the space between a pair of adjacent lower tabs 818and a pair of upper tabs 820 under a commissure 810, and then along thelower tab 818 and the cusp edge portion of the adjacent leaflet 814. Insome embodiments, a single reinforcing chord 866 extends continuouslyalong the cusp edge portions 816 of all of the leaflets and through thespaces beneath each commissure 810. In other embodiments, pluralreinforcing chords 866 can be used, with one reinforcing chord securedto the cusp edge portion of each leaflet. Where multiple reinforcingchords 866 are used, the ends of each chord can be connected (e.g., bytying or knotting) to adjacent ends of the other chords. For example,adjacent ends of two chords can be connected to each in the spaceunderneath a commissure.

FIGS. 69, 72 and 73 illustrate the connection of the connecting skirts860 to the frame 12, according to one embodiment. As shown, theconnecting skirt can be sutured to struts 22 of the frame forming adiagonal line extending from a commissure 810 to the inflow end of theframe. In particular embodiments, one or both layers 864 a, 864 b of theconnecting skirt can be secured to junctions 856 (FIG. 71) by individualstitches 872, and further with whip stiches 874 that are formed alongthe length of a struts 22 between two junctions 856. Each whip stitch874 can extend through an edge portion 870 and around a strut 22multiple times along the length of the strut. The whip stitches 874optionally can extend through the cusp edge portion 816, as depicted inFIG. 69.

In alternative embodiments, the cusp edge portions 816 of the leaflets814 can be mounted to the frame and/or the inner layer 804 of thesealing member using any of the techniques described herein. Forexample, any of the techniques or configurations described above withrespect to FIGS. 10-12B or 14-32 can be used to mount the leaflets 814to the frame 12, without or without a reinforcing chord 866.

As discussed above in connection with the embodiment shown in FIGS.33-37, the folded lower tabs 818 help reinforce the connection betweenthe cusp edge portions 816 of the leaflets and the frame along the uppersections of the cusp edge portions adjacent the commissures 810. Thefolded lower tabs 304 also move the bending axes of the upper sectionsof the cusp edge portions inwardly and away from the inner surface ofthe frame to prevent or minimize contact between the leaflets and theframe in the areas below the commissures. In the illustrated.embodiment, each lower tab 818 forms one additional layer of leafletmaterial on the upper (outflow) surface of the leaflet. In alternativeembodiments, each lower tab 818 can be configured to form multipleadditional layers of leaflet material, such as two, three, or fourlayers, on the upper surface of the leaflet to move the bending axes ofthe leaflet below the commissures even further away from the innersurface of the frame.

The side edges 819 between the lower and upper tabs 818, 820 can be leftunattached to the frame of the prosthetic valve, as best shown in FIG.67 and as previously described with respect to the configuration shownin FIG. 1C. As previously described, the unattached side edges 819 allowgreater elongation or stretching of the leaflets in the axial directionwhen the prosthetic valve is compressed and allowing greater elongationor stretching of the leaflets in the radial direction when theprosthetic valve is expanded. During diastole, the adjacent side edges819 can coapt with each other and prevent retrograde blood from flowingbetween the side edges 819. During systole, the adjacent side edges 819can separate from each other and allow antegrade blood to flow betweenside edges 819 and help wash away blood from the areas underneath thecommissures 810,

After the leaflet assembly (the leaflets 814 and the connecting skirts860) is mounted to the frame, the sealing member 802 can be placed overand mounted to the frame as described above in connection with FIGS.60-64. The triangular-shaped portions 808 of the inner layer 804 of thesealing member can be sutured to struts 22 of the frame and/or to one orboth layers 864 a, 864 b of connecting skirts 860 with sutures 870 (seeFIG. 69).

FIGS. 79-80 shows a prosthetic valve 900, according to anotherembodiment. The prosthetic valve 900 can similar to the prosthetic valve10 described above except for the configuration of the sealing member.The prosthetic valve 900 in the illustrated embodiment comprises asealing member 902 comprising a first layer 902 and a second layer 904,both of which are mounted on the outside of a frame 12. The first layer902 comprises a plurality of diamond-shaped first portions 908 connectedto each other at their upper (outflow) ends. The second layer 904comprises a plurality of triangular-shaped portions 910 connected toeach other at their lower (inflow) ends. The triangular-shaped portions910, which are circumferentially aligned with commissures 906 of theprosthetic valve, are interspersed between the diamond-shaped portions908, which are circumferentially aligned with the leaflets 20. As shown,the diamond-shaped portions 908 and the triangular-shaped portions 910can overlap each to some extent in the vicinity of the commissures 906.

The triangular-shaped portions 910 generally correspond to the shape ofthe space between adjacent leaflets 20. The lower (inflow) end of thesecond layer 904 can be secured to the inflow end of the frame (e.g.,with sutures). The lower edge portions 102 of the leaflets 20 can becoupled to the frame 12, such as with connecting skirts 100 aspreviously described, and the connecting skirts 100 can be secured tothe sides of the triangular-shaped portions 910 (e.g., with sutures)through the cells of the frame. In this manner, the triangular-shapedportions 910 block antegrade blood from flowing outwardly through thecells the frame. The triangular-shaped portions 910 can also engagesurrounding tissue to help seal the prosthetic valve and inhibitparavalvular leakage in conjunction with the diamond-shaped portions908.

The first layer 902 can be secured to the frame 12 (e.g., with sutures)at the inflow end of each diamond-shaped portion 908 and at junctions912 where the diamond-shaped portion 908 are connected to each otheralong the outflow edge of the first layer. The diamond-shaped portions908 are configured to extend radially away from the frame to engage andseal with surrounding tissue when the prosthetic valve is deployed. Theoutflow edge of the first layer 902 between junctions 912 can remainunattached to the frame to receive retrograde blood between the firstlayer 902 and the frame. In some embodiments, the diamond-shapedportions 908 are configured to form an annular wave shape around theoutside of the frame, as depicted in FIG. 67. In some embodiments, theoutflow edge of the first layer 902 also can be secured to the frame(e.g., with sutures) at locations 914 between the junctions 912 toinduce the first layer 902 to assume the wave shape when the prostheticvalve is expanded.

Although in the illustrated embodiment the first layer hasdiamond-shaped portions and the second layer has triangular shapedportions, other shapes are possible. For example, the sections 908, 910of the first and second layers, can be square, oval, rectangular,circular, or combinations of one or more of these shapes.

In alternative embodiments, the sections 908 of the first layer 902 canbe separate pieces of material that are not connected to each other.Similarly, the sections 910 of the second layer 904 can be separatepieces of material that are not connected to each other. For example,FIGS. 81-82 show a prosthetic valve 1000 comprising a sealing member inthe form of alternating diamond-shaped portions 1002 andtriangular-shaped portions 1004 positioned around the outside of theframe. The diamond-shaped portions 1002 can be circumferentially alignedwith the leaflets 20 and the triangular-shaped portions 1004 can becircumferentially aligned with the commissures 1006 of the leaflets.Each portion 1002, 1004 can be a separate piece of material that issutured or otherwise secured to a frame 12 at its inflow and outflowends. The diamond-shaped portions 1002 and the triangular-shapedportions 1004 can extend away from the frame 12 and engage surroundingtissue when the prosthetic valve is expanded.

FIGS. 83-84 shows a prosthetic valve 1100, according to anotherembodiment. The prosthetic valve 1100 can include a sealing member 1102mounted to the frame 12 as described above in connection with theembodiment of FIGS. 60-63. The prosthetic valve 1100 can includeleaflets 1114 connected to each other at their outflow ends to formcommissures 1110 that are mounted to the cells at the outflow end of theframe. The commissures 1110 can be formed by folding commissure tabs ofthe leaflets and securing them to a commissure attachment member 1112,which is then mounted to the frame. Each leaflet 1114 can have a loweror cusp edge portion 1116 that is folded upwardly toward the outflow endof the frame 12 as previously described and secured to the frame with arespective connecting skirt 1118, such as described above in connectionwith FIGS. 69-73. Any of the other techniques for mounting the cusp edgeportions of the leaflets to the frame disclosed herein also can be used.

FIGS. 85-86 show a commissure 1110 formed from two leaflets 1114. Asshown, each leaflet can have a commissure tab folded to form a firstlayer 1120, a second layer 1122, and a third layer 1124. Reinforcementmembers 1126 can be positioned between the second and third layers 1122,1124. The commissure attachment member 1112 can be folded to form acenter portion 1128, two side flaps 1130, and two pairs of fold layers1132, 1134 that extend radially alongside third layers 1124 of theleaflets. The leaflets layers 1120, 1122, 1124 and the layers 1132, 1134of the commissure attachment member 1112 can be secured to each otherwith one or more sutures 1136 and 1138. Each suture 1136, 1138 can formmultiple in and out stitches that extend through all of these layers. Asshown in FIG. 86, suture 1136 can form a stitch that extends over theupper edges of leaflet layers 1120, 1122, 1124. The side flaps 1130 canbe sutured to the struts 22 of the frame, as shown in FIGS. 72 and 77.

As shown in FIG. 85, each leaflet can have opposing recessed side edges1140 underneath each commissure that can remain unattached to the frameto promote blood flow in the areas underneath the commissures, aspreviously described. Each leaflet can also have opposing lower tabs1142 (FIG. 84) similar to lower tabs 818 of prosthetic valve 800. Areinforcing chord, such as reinforcing chord 866 can be secured to thecusp edge portions 1116 of the leaflets as described above in connectionwith prosthetic valve 800.

Any of various delivery techniques can be used to deliver any of theprosthetic heart valves disclosed herein. In a retrograde approach, aprosthetic valve can be mounted in a radially compressed state along thedistal end portion of the delivery catheter, and the delivery catheterand the prosthetic valve can be advanced through the aorta to the nativeaortic valve. Once the prosthetic valve is positioned within the nativeaortic valve, the prosthetic valve can be expanded, such as by inflatinga balloon or another expansion device.

As noted above, any of the prosthetic valves disclosed herein can beconfigured to be self-expandable or can be expandable by applying anexpansion force with a balloon or another type of expansion mechanism.An example of a delivery catheter that has an inflatable balloon forimplanting a plastically-expandable prosthetic heart valve (which can beused for implanting any of the prosthetic valves disclosed herein) isdisclosed in U.S. Patent Application Publication No. 2017/0065415, whichis incorporated herein by reference. An example of a delivery catheterthat can be used to deliver a self-expandable prosthetic heart valve(which can be used for implanting any of the prosthetic valves disclosedherein) is disclosed in U.S. Patent Application Publication No.2014/0343670, which is incorporated herein by reference.

GENERAL CONSIDERATIONS

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatus, and systems should not be construed asbeing limiting in any way. Instead, the present disclosure is directedtoward all novel and nonobvious features and aspects of the variousdisclosed embodiments, alone and in various combinations andsub-combinations with one another. The methods, apparatus, and systemsare not limited to any specific aspect or feature or combinationthereof, nor do the disclosed embodiments require that any one or morespecific advantages be present or problems be solved.

A prosthetic heart valve according to the present disclosure cancomprise a radially collapsible and expandable annular frame, a valvularstructure (e.g., one or more leaflets) mounted within the frame, and oneor more of the novel features described above, including, but notlimited to, any of the sealing members described above, any of thespecific leaflet configurations described above, any of theconfigurations for commissures described above, any of theconfigurations for connecting the cusp edge portions of leaflets to theframe, and/or combinations thereof.

Although the operations of some of the disclosed embodiments aredescribed in a particular, sequential order for convenient presentation,it should be understood that this manner of description encompassesrearrangement, unless a particular ordering is required by specificlanguage set forth below. For example, operations described sequentiallymay in some cases be rearranged or performed concurrently. Moreover, forthe sake of simplicity, the attached figures may not show the variousways in which the disclosed methods can be used in conjunction withother methods. Additionally, the description sometimes uses terms like“provide” or “achieve” to describe the disclosed methods. These termsare high-level abstractions of the actual operations that are performed.The actual operations that correspond to these terms may vary dependingon the particular implementation and are readily discernible by one ofordinary skill in the art.

As used in this application and in the claims, the singular forms “a,”“an,” and “the” include the plural forms unless the context clearlydictates otherwise. Additionally, the term “includes” means “comprises.”Further, the terms “coupled” and “associated” generally meanelectrically, electromagnetically, and/or physically (e.g., mechanicallyor chemically) coupled or linked and does not exclude the presence ofintermediate elements between the coupled or associated items absentspecific contrary language.

As used herein, the term “proximal” refers to a position, direction, orportion of a device that is closer to the user and further away from theimplantation site. As used herein, the term “distal” refers to aposition, direction, or portion of a device that is further away fromthe user and closer to the implantation site. Thus, for example,proximal motion of a device is motion of the device toward the user,while distal motion of the device is motion of the device away from theuser. The terms “longitudinal” and “axial” refer to an axis extendinglengthwise of a component, usually in the proximal and distaldirections, unless otherwise expressly defined.

In view of the many possible embodiments to which the principles of thedisclosed invention may be applied, it should be recognized that theillustrated embodiments are only preferred examples of the invention andshould not be taken as limiting the scope of the invention. Rather, thescope of the invention is defined by the following claims. We thereforeclaim as our invention all that comes within the scope and spirit ofthese claims.

We claim:
 1. A prosthetic heart valve comprising: an annular framecomprising an inflow end and an outflow end and being radiallycollapsible and expandable between a radially collapsed configurationand a radially expanded configuration, wherein the frame comprises aplurality of struts defining openings; a valvular structure mountedwithin the frame and comprising a plurality of leaflets that regulatethe flow of blood through the frame, wherein each leaflet comprises aninflow surface, an outflow surface, and a cusp edge portion that isfixed relative to the frame; a sealing member mounted on the frame andcomprising an inner layer and an outer layer, wherein at least the outerlayer is mounted on the outside of the frame, and the inner layer coversat least the openings in the frame between adjacent cusp portions ofadjacent leaflets and the inner layer does not cover one or moreopenings in the frame at locations facing the outflow surfaces of theleaflets to permit retrograde blood to flow through the one or moreuncovered openings in the frame and into space between the outer layerand the frame.
 2. The prosthetic heart valve of claim 1, wherein thecusp edge portions of the leaflets have a curved, scalloped shape andthe inner layer of the sealing member comprises a plurality oftriangular shaped portions that are mounted on the frame at locationsbetween adjacent cusp edge portions of adjacent leaflets.
 3. Theprosthetic heart valve of claim 2, wherein the inner layer does notcover any openings in the frame at locations facing the outflow surfacesof the leaflets.
 4. The prosthetic heart valve of claim 1, wherein theinner layer is mounted on the outer surface of the frame.
 5. Theprosthetic heart valve of claim 1, wherein the inner layer is mounted onthe inner surface of the frame.
 6. The prosthetic heart valve of claim1, wherein the outer layer is shape set such that it extends radiallyaway from the frame when the frame is in the radially expandedconfiguration.
 7. The prosthetic heart valve of claim 6, wherein theouter layer comprises a shape set fabric.
 8. The prosthetic heart valveof claim 1, wherein the outer layer comprises a lower tapered wallsection that extends outwardly from the frame in a direction from theinlet end to the outlet end, an upper tapered wall section that extendsoutwardly from the frame in a direction from the outlet end to the inletend, and a central wall section that extends between the lower and uppertapered wall sections.
 9. The prosthetic heart valve of claim 1, whereinthe cusp edge portion of each leaflet is fixed relative to the frame bya connecting skirt that is connected to and disposed between the frameand the cusp edge portion of the leaflet, wherein each connecting skirtis sutured to struts of the frame extending in a diagonal line from theinlet end to the out end of the frame.
 10. The prosthetic heart valve ofclaim 9, wherein each connecting skirt comprises two layers of materialsutured to the cusp edge portion of a leaflet and to struts of theframe.
 11. The prosthetic heart valve of claim 1, wherein each leafletcomprises opposing upper tabs on opposite sides of the leaflet andopposing lower tabs on opposite sides of the leaflets below the uppertabs, wherein each upper tab is paired with an adjacent upper tab of anadjacent leaflet to form a plurality of commissures, and wherein eachlower tab is folded to form at least one fold layer along the cusp edgeportion of the respective leaflet.
 12. The prosthetic heart valve ofclaim 11, wherein each leaflet is unattached to the frame at locationsbetween the upper tabs and the lower tabs.
 13. The prosthetic heartvalve of claim 12, wherein each leaflet is formed with a gap between theupper tab and the lower tab on each side of the leaflet.
 14. Theprosthetic heart valve of claim 11, further comprising at least onereinforcing chord extending along the cusp edge portion of each leafletand underneath each commissure.
 15. A prosthetic heart valve comprising:an annular frame comprising an inflow end and an outflow end and beingradially collapsible and expandable between a radially collapsedconfiguration and a radially expanded configuration; and a valvularstructure mounted within the frame and comprising a plurality ofleaflets that regulate the flow of blood through the frame, wherein eachleaflet comprises opposing upper tabs on opposite sides of the leaflet,opposing lower tabs on opposite sides of the leaflets below the uppertabs, a cusp edge portion extending between the lower tabs, the cuspedge portion being fixed relative to the frame, wherein each upper tabis paired with an adjacent upper tab of an adjacent leaflet to form aplurality of commissures that are fixed relative to the frame, andwherein each lower tab is folded to form at least one fold layer alongthe cusp edge portion of the respective leaflet.
 16. The prostheticheart valve of claim 15, wherein opposing side edges of the leafletsbetween the upper tabs and the lower tabs are unattached to the frame.17. The prosthetic heart valve of claim 16, wherein the opposing sideedges of the leaflets are formed with gaps between the upper tabs andthe lower tabs where the side edges are unattached to the frame.
 18. Theprosthetic heart valve of claim 15, further comprising a sealing membermounted on the frame and comprising an inner layer and an outer layer,wherein at least the outer layer is mounted on the outside of the frame,and the inner layer covers at least openings in the frame betweenadjacent cusp edge portions of adjacent leaflets and the inner layer hasuncovered areas at locations facing the outflow surfaces of the leafletsto permit retrograde blood to flow through the openings in the frame andinto space between the outer layer and the frame.
 19. The prostheticheart valve of claim 15, further comprising a reinforcing chordextending along and secured to the cusp edge portion of each leaflet andthe at least one fold layer of each lower tab.
 20. A prosthetic heartvalve comprising: an annular frame comprising an inflow end and anoutflow end and being radially collapsible and expandable between aradially collapsed configuration and a radially expanded configuration;and a valvular structure mounted within the frame and comprising aplurality of leaflets that regulate the flow of blood through the frame,wherein each leaflet comprises opposing tabs on opposite sides of theleaflet and a cusp edge portion between the tabs, the cusp edge portionbeing fixed relative to the frame, wherein each tab is paired with anadjacent tab of an adjacent leaflet to form a plurality of commissuresthat are fixed relative to the frame, and wherein each leaflet hasopposing edges between the tabs and the cusp edge portions that areunattached to the frame, allowing blood to flow between the frame andthe unattached edges.
 21. The prosthetic heart valve of claim 20,wherein the unattached edges are spaced radially inwardly of the frame.22. The prosthetic heart valve of claim 20, wherein the tabs of eachleaflet comprise upper tabs that are paired with adjacent upper tabs ofadjacent leaflets to form the commissures, and each leaflet furthercomprises opposing lower tabs on opposite sides of the leaflets belowthe upper tabs, the lower tabs being spaced from the upper tabs by theunattached edges, wherein the lower tabs are folded against the cuspedge portion of the leaflet.
 23. The prosthetic heart valve of claim 20,further comprising a reinforcing chord extending along and secured tothe cusp edge portion of each leaflet and traversing the spaceunderneath each commissure.
 24. The prosthetic heart valve of claim 20,wherein each unattached edge of a leaflet can coapt with an adjacentunattached edge of an adjacent leaflet under the flow of retrogradeblood and can separate from the adjacent unattached edge under the flowof antegrade blood.
 25. A prosthetic heart valve comprising: an annularframe comprising an inflow end and an outflow end and being radiallycollapsible and expandable between a radially collapsed configurationand a radially expanded configuration, wherein the frame comprises aplurality of struts; a valvular structure mounted within the frame andcomprising a plurality of leaflets that regulate the flow of bloodthrough the frame, wherein each leaflet comprises opposing tabs onopposite sides of the leaflet and a cusp edge portion between the tabs,wherein each tab is paired with an adjacent tab of an adjacent leafletto form a plurality of commissures that are connected to the frame; andwherein the cusp edge portion of each leaflet is connected to the frameby a connecting skirt that is connected to and disposed between theframe and the cusp edge portion of the leaflet, wherein each connectingskirt is sutured to struts of the frame extending in a diagonal linefrom the inlet end to the out end of the frame.
 26. The prosthetic heartvalve of claim 25, wherein the cusp edge portion of each leaflet isfolded toward the outlet end of the frame.
 27. The prosthetic heartvalve of claim 26, further comprising a reinforcing chord secured toeach cusp edge portion opposite a respective connecting skirt, thereinforcing chord defining a bending axis for a respective leaflet. 28.The prosthetic heart valve of claim 25, wherein each connecting skirtcomprises two layers of material sutured to the cusp edge portion of aleaflet and to the frame.
 29. The prosthetic heart valve of claim 25,wherein the cusp edge portions are not supported by any metal componentsinside the frame.
 30. A prosthetic heart valve comprising: an annularframe comprising an inflow end and an outflow end and being radiallycollapsible and expandable between a radially collapsed configurationand a radially expanded configuration, wherein the frame comprises aplurality of struts defining openings; a valvular structure mountedwithin the frame and comprising a plurality of leaflets that regulatethe flow of blood through the frame, wherein each leaflet comprises aninflow surface, an outflow surface, opposing upper tabs on oppositesides of the leaflet, opposing lower tabs on opposite sides of theleaflets below the upper tabs, a cusp edge portion extending between thelower tabs, wherein each upper tab is paired with an adjacent upper tabof an adjacent leaflet to form a plurality of commissures that are fixedrelative to the frame, and wherein each lower tab is folded to form atleast one fold layer along the cusp edge portion of the respectiveleaflet; wherein the cusp edge portion of each leaflet is connected tothe frame by a connecting skirt that is connected to and disposedbetween the frame and the cusp edge portion of the leaflet, wherein eachconnecting skirt is sutured to struts of the frame extending in adiagonal line from the inlet end to the out end of the frame; whereineach leaflet has opposing edges between the upper tabs and the lowertabs that are unattached to the frame, the unattached edges being spacedradially inwardly of the frame, allowing blood to flow between the frameand the unattached edges; and a sealing member mounted on the frame andcomprising an inner layer and an outer layer, wherein at least the outerlayer is mounted on the outside of the frame, and the inner layer coversat least the openings in the frame between adjacent cusp portions ofadjacent leaflets and the inner layer does not cover one or moreopenings in the frame at locations facing the outflow surfaces of theleaflets to permit retrograde blood to flow through the one or moreuncovered openings in the frame and into space between the outer layerand the frame.